この作品は、米国陸軍研究所、アデルフィ、MD、米国、グラント W91ZLK-12-P-0447 下によって支えられました。ミハエル石とアンソニー ・ ブロックの助けを借りて共鳴測定を行った。ジョージ ・ ワシントン大学からデイモン コノバーの助けを借りて、サーマル カメラ計測を行った。

1. 選択と最適構造の設計
<ol><li>広い範囲の周波数の固定固定ビームを選択 (他の候補者と比較して、それにより様々 なチューニングの周波数 (TCF) とごくわずかの熱膨張係数の大きな温度係数のため加熱時)。</li>
	<li>目的は効率化のチューニングの場合は、長い梁を設計します。目的が周波数ホッピングまたは信号追跡アプリケーションの場合は、短いビームをデザインします。</li>
</ol>2. モデリングと相補型金属酸化膜半導体 (CMOS) の製作
<ol><li>設計し、有限要素法プログラムで MEMS フィルターの 3 D モデルを作成します。</li>
	<li>集積回路 (IC) のデザイン ツールは、gds ファイルを作成する層で同じレイアウトを再構築します。</li>
	<li>この gds ファイルを作製 (我々 は 0.6 μ m cmos を使用) の CMOS 鋳造を提出します。</li>
	<li>CMOS プロセスが完了したら、後処理で続行 (チップは、多結晶シリコン、アルミニウムおよび酸化物の層があるに注意してください)。<ol>
<li>行為 CHF3/O2ドライ エッチング プロセスを介して誘導結合プラズマ (ICP) etch システム。アルミ層間 SiO2をエッチングし、5.7 のアスペクト比のビームを形成します。このプロセスは、次のパラメーターを使用して: CHF3 40 sccm、O2 5 sccm で、0.5 圧力 Pa、500 W、ICP パワーと 56 分の合計で 100 W でサンプル パワー エッチング時間。</li>
		<li>適用、XeF2梁下 9 μ m 深さキャビティを作成するシリコン基板のエッチングします。このプロセスでは、60 秒/サイクルの 3 t、3 サイクルのエッチング装置 XeF2を使用します。</li>
	</ol>
</li>
	<li>走査型電子顕微鏡 (SEM) 正しく作製したことを確認するとデバイスを特徴付けます。この手順変更 2.58 に加速電圧ビーム kV と 9.5 mm の作動距離。</li>
</ol>3. デバイスのテスト
メモ: デバイスのテスト ジュール加熱試験および周波数応答試験を含む多くの手順で構成されます。
<ol><li>
埋め込みヒーター用サーマル カメラ テスト
	<ol>
<li>チップの上にサーマル カメラを置き、彼らはビームを加熱できるように埋め込みヒーターをテストします。</li>
		<li>チップ パッケージに電源を接続し、ビーム全体の温度上昇を少しずつ 5.7 V を 0 V から埋め込みヒーターの DC 電圧を適用します。</li>
		<li>暖房プロセスの間に熱カメラを介してチップ パッケージ全体の温度プロファイルを記録します。数値計算プログラムの結果を保存し、加熱プロファイルをプロットします。</li>
	</ol>
</li>
	<li>
レーザドップラ振動計とテストのセットアップを調整
	<ol>
<li>120 μ m の長い梁の上にレーザーを配置します。</li>
		<li>両方の 7 V DC を適用する 2 つの 120 μ m の長い梁と共鳴操作の 3 V AC 電圧の電源を接続します。追加の DC バイアス電圧を最大 5.7 ジュール共鳴操作中に梁に熱を適用する V の埋め込みヒーターに接続します。</li>
		<li>低ノイズ レーザーの反射を取得するビームにレーザーを別の場所に移動します。雑音を低減する青色のバーの強度を増加することを確認します。</li>
		<li>画面を調整し、測定のセットアップを開始する複数のビューに分割します。</li>
		<li>取得設定に移動、FFT に測定モードを設定、任意のフィルターを使用していない 2 つの mhz の帯域幅を設定します。</li>
		<li>2.5 MHz の最大周波数をサポートできますよう、速度を変更します。</li>
		<li>定期的なチャープ波形を使用します。 注: ここでは、振幅は AC 電圧の略し、オフセット電圧の略します。</li>
		<li>この新しい設定は、測定を開始します。</li>
		<li>直流電圧を 1 V に変更することで取得設定を更新します。</li>
		<li>代入は、Ref1 を示す赤い警報 (つまり信号が騒々しいということ) とき取得設定ウィンドウでバイアス印加電圧が低下します。</li>
		<li>さらに信号対雑音比を高めるビームにレーザーを別の場所に移動します。時折、可能性があります悪いスポット振動バーに赤い警報を引き起こすビームこの場合は、最高のスポットを検索し続けます。</li>
	</ol>
</li>
	<li>
LDV による 68 μ m 長い MEMS フィルターのテスト
	<ol>
<li>テスト用 68 μ m 長い MEMS フィルターを選択します。</li>
		<li>25 V の直流電圧と 5 V AC 電圧 2 68 μ m 長い隣接する梁の間に適用されます。ここでは、DC 電圧は、曲げと AC 電圧共振操作が可能します。</li>
		<li>68 μ m の長いビームは、埋め込みヒーターに追加の DC 電圧を適用し、少しずつ 5.7 V を 0 V から電圧を高めます。これは加熱周波数チューニング ジュールに基づいて提供されます。</li>
		<li>観察し共振周波数と各ステップで応用バイアス電圧に対する位相応答を記録およびテーブルの結果を集計します。ここでは、このサンプルの全周波数チューニングです 874 kHz 付近 5.7 V の DC 電圧が埋め込みヒーターに適用されます。 注: (右側) のシミュレーションと実測 (レフト側) が同期されます。</li>
	</ol>
</li>
	<li>
高いモード測定
	<ol>
<li>セクション 3.2 に示す取得設定ウィンドウに移動する/D ボタンを押すし、それは非常に高い周波数をサポートできるように、速度を変更します。</li>
		<li>最初のフェーズと 2 番目のモードを測定します。 注: 主共振変位モード 1 の Y 方向は、モード 2 の Z 方向 (つまり顕微鏡の方で) です。</li>
	</ol>
</li>
</ol>4. デバイスの障害を回避します。
<ol><li>
ヘッドス ライダーを解決するために低周波の方形波信号のアプリケーション
	<ol>
<li>2 つの隣接するビーム間静電充電に起因する粘着の問題を解決する 1 Hz 方形波信号を適用します。</li>
		<li>オフセットのボックスに移動し、1 V AC 電圧を維持しながら直流電圧を 1 V に設定します。</li>
		<li>[頻度] ボックスに移動し、周波数を 1 Hz に設定。</li>
		<li>アクティブにし、梁をこの新しい設定を適用します。</li>
		<li>ビームの分離を観察します。</li>
	</ol>
</li>
	<li>
高熱応力と燃焼
	<ol>
<li>熱ストレス テストのため余分なサンプルを使用します。</li>
		<li>高熱応力によるデバイスが失敗する前に最大許容電圧を見つける小さなずつ埋め込みヒーター バイアス印加電圧を増加させます。</li>
	</ol>
</li>
</ol>5. チューニング機能を高める
<ol><li>合計 661 kHz 周波数シフトの 5.7 V を 0 V から埋め込みヒーター バイアス印加電圧を増加させながら 2 つ 68 μ m 隣接する梁の間一緒に 25 V DC 電圧と 5 V AC 電圧を適用されます。</li>
	<li>35 V 1 V AC 電圧を適用する埋め込みヒーターに同じバイアス電圧設定を維持し、ながら、2 つの 68 μ m 長い隣接ビーム間効果を軟化付加ばねを追加する 25 V から応用のバイアス電圧を増加します。</li>
	<li>661 kHz から軟化効果追加今春から 875 の kHz に増やす必要があります合計周波数シフトに 32% の改善を記録します。 注: 我々 の知る限り、この作品で初めて実現した MEMS 共振器のチューニング機能の変更します。</li>
</ol>

<ol><li>Göktaş, H., Turner, K., Zaghloul, M. <a target="_blank" href="http://ieeexplore.ieee.org/document/7762782/">Enhancement in CMOS-MEMS Resonator for High Sensitive Temperature Sensing.</a> IEEE Sensors J. 17 (3), 598-603 (2017).</li>
<li>Davila, A. P., Jang, J., Gupta, A. K., Walter, T., Aronson, A., Bashir, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Microresonator+mass+sensors+for+detection+of+Bacillus+anthracis+Sterne+spores+in+air+and+water%5BTitle%5D)+AND+%22Biosens.+Bioelectron%22%5BJournal%5D)">Microresonator mass sensors for detection of Bacillus anthracis Sterne spores in air and water.</a> Biosens. Bioelectron. 22 (12), 3028-3035 (2007).</li>
<li>Lee, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Suspended+microchannel+resonators+with+piezoresistive+sensors%5BTitle%5D)+AND+%22Lab+Chip%22%5BJournal%5D)">Suspended microchannel resonators with piezoresistive sensors.</a> Lab Chip. 11 (4), 645-651 (2011).</li>
<li>Arash, H., Pourkamali, S. <a target="_blank" href="http://ieeexplore.ieee.org/document/6111426/">Fabrication and Characterization of MEMS-Based Resonant Organic Gas Sensors.</a> IEEE Sensors J. 12 (6), 1958-1964 (2012).</li>
<li>Göktaş, H., Zaghloul, M. <a target="_blank" href="http://ieeexplore.ieee.org/document/6985576/">Tuning In-Plane Fixed-Fixed Beam Resonators with Embedded Heater in CMOS Technology.</a> IEEE Electron Device Lett. 36 (2), 189-191 (2015).</li>
<li>Li, C. S., Hou, L. J., Li, S. S. <a target="_blank" href="http://ieeexplore.ieee.org/document/6112657/">Advanced CMOS-MEMS Resonator Platform.</a> IEEE Electron Device Lett. 33 (2), 272-274 (2012).</li>
<li>Li, M. H., Chen, W. C., Li, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Mechanically+Coupled+CMOS-MEMS+Free-Free+Beam+Resonator+Arrays+With+Ehanced+Power+Handling+Capability%5BTitle%5D)+AND+%22IEEE+Trans.+Ultrason.+Ferroelect.+Freq.+Control%22%5BJournal%5D)">Mechanically Coupled CMOS-MEMS Free-Free Beam Resonator Arrays With Ehanced Power Handling Capability.</a> IEEE Trans. Ultrason. Ferroelect. Freq. Control. 59 (3), 346-357 (2012).</li>
<li>Lopez, J. L., et al. <a target="_blank" href="http://ieeexplore.ieee.org/abstract/document/5109806/">A CMOS-MEMS RF-Tunable Bandpass Filter Based on Two High-Q 22-MHz Polysilicon Clamped-Clamped Beam Resonators.</a> IEEE Electron Device Lett. 30 (7), 718-720 (2009).</li>
<li>Khine, L., Palaniapan, M. <a target="_blank" href="http://iopscience.iop.org/article/10.1088/0960-1317/19/1/015017/meta">High-Q bulk-mode SOI square resonator with straight-beam anchors.</a> J. Micromech. Microeng. 19 (1), (2009).</li>
<li>Manca, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Programmable+mechanical+resonances+in+MEMS+by+localized+joule+heating+of+phase+change+materials%5BTitle%5D)+AND+%22Adv.+Mater%22%5BJournal%5D)">Programmable mechanical resonances in MEMS by localized joule heating of phase change materials.</a> Adv. Mater. 25 (44), 6430-6435 (2013).</li>
<li>Rúa, A., et al. <a target="_blank" href="http://aip.scitation.org/doi/abs/10.1063/1.4716191?journalCode=jap">Phase transition behavior in microcantilevers coated with M1-phase VO2 and M2-phase VO2:Cr thin films.</a> J. Appl. Phys. 111 (10), 104502(2012).</li>
<li>Remtema, T., Lin, L. <a target="_blank" href="http://www.sciencedirect.com/science/article/pii/S0924424701006033">Active frequency tuning for micro resonators by localized thermal stressing effects.</a> Sens. Actuators A, Phys. 91 (3), 326-332 (2001).</li>
<li>Göktaş, H., Zaghloul, M. <a target="_blank" href="http://onlinelibrary.wiley.com/doi/10.1002/2015RS005893/abstract">The Implementation of Low Power and Wide Tuning Range MEMS filters for Communication Applications.</a> Radio Sci. 51 (10), 1636-1644 (2016).</li>
<li>Göktaş, H., Zaghloul, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+Novel+Microhotplate%3A+A+Design+Featuring+Ultra+High+Temperature%2C+Ultra+Low+Thermal+Stress%2C+Low+Power+Consumption+and+Small+Response+Time%5BTitle%5D)+AND+%22Sensor+Comm%22%5BJournal%5D)">The Novel Microhotplate: A Design Featuring Ultra High Temperature, Ultra Low Thermal Stress, Low Power Consumption and Small Response Time.</a> Sensor Comm. , (2013).</li>
<li>Kushmerick, J. G., et al. <a target="_blank" href="https://link.springer.com/article/10.1023/A%3A1009082530479">The influence of coating structure on micromachine stiction.</a> Tribol Lett. 10 (1), (2001).</li>
<li>Kim, J. M., et al. <a target="_blank" href="http://iopscience.iop.org/article/10.1088/0960-1317/12/5/327/meta">Continuous anti-stiction coatings using self-assembled monolayers for gold microstructures.</a> J. Micromech. Microeng. 12 (5), 688-695 (2002).</li>
<li>Bhattacharya, E., et al. <a target="_blank" href="http://onlinelibrary.wiley.com/doi/10.1002/pssa.200461149/abstract">Effect of porous silicon formation on stiction in surface micromachined MEMS structures.</a> Phys. Stat. Sol. (A). 202 (8), 1482-1486 (2005).</li>
<li>Koppaka, S. B., Phinney, L. M. <a target="_blank" href="http://ieeexplore.ieee.org/document/1416917/">Release Processing Effects on Laser Repair of Stiction-Failed Microcantilevers.</a> J. Microelectromech. Syst. 14 (2), 410-418 (2005).</li>
<li>Ghatkesar, M. K., et al. <a target="_blank" href="https://www.semanticscholar.org/paper/Higher-modes-of-vibration-increase-mass-sensitivit-Ghatkesar-Barwich/b50ed2d5233ea10271788baa70517f97d465d3aa">Higher modes of vibration increase mass sensitivity in nanomechanical microcantilevers.</a> Nanotechnology. 18 (44), 445502(2007).</li>
<li>Göktaş, H., Mona, Z. <a target="_blank" href="http://ieeexplore.ieee.org/document/6688202/">High Sensitivity CMOS Portable Biosensor with Flexible Microfluidic Integration.</a> IEEE SENSORS. , (2013).</li>
</ol>

何を開示する必要があります。

MEMS フィルターを構築する上で重要な手順の 1 つアプリケーション領域に基づいてデバイスを設計することです。ビームは、長いまたはシンナーより効率 (ppm/mW)、短いまたは周波数ホッピングまたは信号追跡アプリケーションのシンナーをチューニングします。同じ方法で LDV による明確なシグナル検出は、デバイスのテストは、少なくとも 3-4 μ m の厚みで梁を設計する方が良いが重要です。それ以外の場合信号はノイズの多い、レンズ、X 100 (LDV ソフトウェアに組み込まれた) ノイズ除去に最適な検出を達成するためにテストの複数のポイントを取ります。その大きな TCF のため (カンチレバー、チューニング フォーク、両端自由はり)、他の候補者と比較して、固定固定ビームにより、幅広い周波数チューニング熱せられると。本研究ではジュール加熱埋め込みヒーターとしてポリシリコン層法を使用しました。
粘着を回避する方法。
粘着は静電帯電効果による共鳴操作中に起こることができます。高剛性定数梁の設計、アンチ粘着化学と表面をコーティング、逆方向に高電圧を適用するなど、文学の多くの異なる方法を提示されています。対照的に、トラブルシューティングに関しては、ここで、簡単に代替法を提案する.短時間(図 1のため比較的高電圧低周波 (1 Hz) 方形波信号を適用することによって)、梁はお互いから分離でき、共鳴し続けます。このソリューションは低コスト設計を可能、反スティック コーティングなどより複雑なソリューションを排除します。
デバイスの障害を回避する方法。
比較的高密度高電圧アプリケーションによる固定固定梁中を流れる電流がデバイスの障害を引き起こす可能性が (または壊れてデバイスを焼け) (図 2)。これは熱膨張定数固定固定のさまざまなレイヤーでの不一致のために主にビーム13,14。エラーを回避するには、各固定固定梁の最大許容電圧に勉強 [最大周波数可変範囲と共に、慎重に定義します。最大許容電圧および消費電力はビームから、デバイス寸法13異なります。この作品で 68 μ m 長の梁の埋め込みヒーターを最大許容電圧は、デバイス障害が発生する前に 6.3 7 V の間です。
効率的な特性:
ネットワーク アナライザー メソッドの最大の課題の一つは、寄生容量を排除することです。IC 設計ツールを使用して、周波数と 120 μ m 長い MEMS フィルターの等価回路の位相応答をプロットします。S21 ピーク-ピーク値激減 6 dB から 0.34 dB に寄生容量増加 1 時でさえ 20 fF MEMS の横に配置、オンチップ アンプ デザインを施行した fF フィルター6,8。
ネットワーク ・ アナライザーと対照をなして LDV は、固定固定梁の共鳴法測定に多くの利点を提供しています。まず、寄生容量がなくなるし、これにより、迅速な試作とはるかに小さいデバイス (高周波デバイス) の評価。また、レーザドップラ振動計ネットワーク アナライザーは最初のモードのみを特徴付ける高モード特性 (図 3) がご利用いただけます。これはバイオ センサー アプリケーション19など様々 な研究分野の多くの利点を提供します。
チューニング機能をチューニングする方法。
我々 の知る限り、この作業5で初めて実証されたチューニング チューニング機能。適用される 2 つの隣接する梁の間 DC バイアス電圧の増加による効果を軟化追加春総周波数可変範囲の 32% の増加を提供します。2 隣接するビーム間直流印加電圧の増加追加春からジュール加熱、軟化の上に軟化を追加しより広い周波数可変範囲でこの結果します。隣接する 2 つのビーム間の DC 電圧は 25 V から 35 V (図 4) に増加するとき、チューニング レンジは 875 khz 661 kHz から増加します。この機能は、周波数ホッピング、追跡、および再構成可能なレシーバーおよびトランシーバー回路などのアプリケーションで大きな需要があることです。
MEMS フィルター ポータブル バイオ センサー アプリケーション2,3,20の特に驚異的な注目を集めています。有限要素法を使用して、高次モード応答を検討します。初期の結果によると高次モードは多くのより良い感度 (最初のモードと比較して 46 回まで改善) を提供できる (図 6)、ポータブル バイオ センサー分野で高価で求められている特性。このため、ここで示した LDV 手法の取り込みは避けられない。高次モードでデバイスの共鳴を測定その機能により高いモードの検出 (図 5) の LDV 関与が必要になります。高次モードで高感度の可能性と共に、LDV のこの印象的な機能は、感度が高い最先端のバイオ センサーをもたらすかもしれない。

その高い信頼性、低消費電力、コンパクト設計、高品質係数、低コストによる MEMS フィルターの需要が高まっています。センサーと無線通信のコア部品として広く使用されます。発振器、フィルター5,6、7、ガス センサー4バイオ センサー2,3温度センサー1は、最も人気のあるアプリケーション領域です。静電 MEMS フィルターの最も人気のある、固定固定ビーム5,8、片持ち2、チューニング フォーク6、両端自由はりの6、7、曲げディスク デザイン7と正方形デザインの9。
(アプリケーション ベースの構造最適化、広い範囲の周波数可変範囲、およびエラーの回避) の設計と特性評価 (高速プロトタイピング、寄生を避けるなど、MEMS フィルターを実現するために多くの重要なステップがあります。キャパシタンス、および検出の高次モード)。製作公差または周囲温度の変動による周波数変更を補うために周波数調整機能が必要です。さまざまなテクニック10、11,12は、この要件に対処するため文献で報告されています。しかし、彼らは限られた周波数チューニング機能、低中心周波数、要件、および外部ヒーター10,11追加の後処理など欠点があります。
この研究では限られた周波数チューニング弾性率による距離を加熱方法5,13ジュールで広い範囲の周波数を提案12 (隣接する 2 つのビーム間の DC バイアス電圧の増加) を変更し、材料はフェーズ遷移法10,11です。また、最適構造選択とアプリケーション ベースの設計は Göktaş と Zaghloul の13にまとめた。ここでは、レーザドップラ振動計の助けを借りて埋め込みヒーターに DC 電圧を増やすことによって固定固定梁の共振周波数を調整する方法を示します。有限要素法 (FEM) 解析シミュレーションは、チューニング機構を可視化するために同じ枠で LDV 計測と同期されます。これはジュール加熱と曲げビーム全体のプロファイルが含まれています。
(焦げたデバイスおよびヘッドス ライダー) の障害と彼らの提案された解決策を述べる。ジュール加熱方式固定固定ビームの高熱応力との組み合わせでさまざまな周波数を提供していますが、同時にによって、特定の温度レベルのデバイスが焦げた。これは異なる材料14間高い熱応力に起因します。ソリューションは、順番 (32%) でチューニングの範囲を増加し、高温のための必要性を排除する 2 つの隣接するビーム間の DC 電圧を増やすことです。この「チューニング チューニング範囲」メソッド最初 Göktaş と Zaghloul5で示した Göktaş Zaghloul13, で詳しく説明、再紹介。粘着、その一方で、起こることができる作製プロセスまたは共鳴操作中に。提案する接着エネルギー15,16、増加表面粗さ17、および18レーザー修復プロセスを減らすために表面のコーティングを適用するなど、この問題に対処するための多くの技術がずっとあります。対照的に、低周波の矩形波信号が接続されている 2 つのビーム間適用された、分離正常に LDV による記録された単純な手法を提案する.このメソッドを排除することができます余分なコストし、設計の複雑さを減らします。
最先端の MEMS フィルターを構築する上での重要なステップは、評価と検証。ネットワーク ・ アナライザーの特性は、最も人気のあると広く使用されている方法の 1 つしかし、それはいくつかの欠点があります。小さくても寄生容量が信号を殺すことができるので、これは通常ノイズ除去のアンプ回路3,6,8を必要とし、最初のモードの共振特性を検出できるだけ。その一方で、ldv の特性はこの寄生容量問題から解放され、多くのより小さい変位を検出することができます。高速プロトタイピング、これにより増幅器の設計の必要性を排除できます。さらに、レーザドップラ振動計は、MEMS フィルターの高い共振モードを検出できます。この機能は、非常に有望な高感度バイオ センサーの分野で特に。高いカンチレバー モードより多くの感度19を提供できます。高いモード ldv 固定固定ビーム測定は示す、FEM シミュレーション測定に適用。有限要素法によるシミュレーションの結果から早期固定固定ビームの最初のモードと比較して感度の 46 回改善を提供しています。

<table><tbody><tr><td>Laser Doppler Vibrometer</td><td>Polytec</td><td>Polytec MSA-500</td><td></td></tr><tr><td>Scanning Electron Microscope</td><td>Zeiss</td><td></td><td></td></tr><tr><td>Thermal Camera</td><td>X</td><td></td><td></td></tr><tr><td>Power Supply&amp;nbsp;</td><td>Egilent</td><td>(E3631A)</td><td></td></tr><tr><td>Microscope</td><td>X</td><td></td><td></td></tr><tr><td>Coventor</td><td>Coventor</td><td></td><td>Simulation Tool</td></tr><tr><td>Cadence Virtuoso</td><td>Cadence</td><td></td><td>Simulation Tool</td></tr><tr><td>Multisim</td><td>Multisim</td><td></td><td>Simulation Tool</td></tr></tbody></table>

design and characterization methodology for efficient wide range tunable mems filters

ここでは、従来手法 (ネットワーク アナライザー) として、アプリケーション ・ ベースの微小電気機械システム (MEMS) フィルターと効率的 (それを使用する方法を作成するテクニックをレーザドップラ (LDV) の利点を示すすなわち、チューニング チューニング機能と障害とヘッドス ライダーの両方を回避する)。レーザドップラ振動計は、高いモードの検出 (高感度バイオ センサー アプリケーション) と非常に小さいデバイス (高速プロトタイピング) の共鳴測定など、ネットワーク アナライザーで実行可能な重要で測定できます。したがって、LDV は周波数チューニング レンジと本研究用に構築された MEMS フィルターの異なるモードで共振周波数を特徴付けるために使用されました。この広い範囲の周波数チューニング メカニズムは、単にジュール加熱埋め込みヒーター固定固定はりの温度に対して比較的高い熱応力からに基づいています。ただし、このメソッドの別の制限がデバイスを書き込むことができますその結果高熱応力であることを示します。さらなる改善は実現され、本研究で初めて表示されるチューニング機能を増加させる 2 つの隣接する梁の間に応用 DC バイアス電圧 (35 V を 25 V) 32% 増加したなど。この重要な発見は、余分なジュールより広い周波数チューニング レンジで加熱の必要性を排除します。別の可能な障害は、粘着や構造最適化の要件: 低周波の方形波信号アプリケーション正常にビームを区切ることができますより多くの必要性を排除の簡便な手法を提案します。文献は、洗練された、複雑なメソッド。上記調査結果を必要とする設計手法と、アプリケーション ベースの設計をいたします。

粘着低周波の方形波信号を適用することで回避されましたし、これは LDV (図 1) を使用して検証しました。高熱応力14埋め込みヒーターに比較的高い DC バイアスを適用するときのための可能な障害は、顕微鏡 (図 2) で確認しました。有限要素法プログラムは、ビーム (図 3) 高次モードを派生に使用されました。レーザドップラ振動計 (図 4) の助けを借りて、この仕事の5で初めて 2 つの隣接する梁の間 DC バイアス電圧 (35 V を 25 V) を変更することでチューニング機能 (32% 増) の変更を示した。レーザドップラ振動計による高次モード応答を測定する機能が正常に示したし、有限要素法によるシミュレーションと比較しました。5番目のモードは、各ビームの複数ポイントを測定レーザドップラ振動計で測定しました。有限要素法によるシミュレーション (図 5) と完全に一致する測定モード形状。また、最大周波数で 46 回向上 1 pg 質量を MEMS フィルターにアタッチしたとき、最初のモードに関してシフトは、有限要素法による示されました。この有望な結果は、レーザドップラ振動計 (図 6) の能力を読んで高次モードと組み合わせればより高感度バイオ センサーを提供します。
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/56371/56371fig1.jpg"> 図 1: MEMS フィルターの粘着します。粘着起こった T = 55 T でリリースされている梁 s = 57 s 低周波の方形波信号を適用した後。<a href="//cloudflare.jove.com/files/ftp_upload/56371/56371fig1large.jpg" target="_blank">この図の拡大版を表示するのにはここをクリックしてください</a>。
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/56371/56371fig2.jpg"> 図 2: MEMS フィルターを通して燃焼します。高い直流電圧を高電圧を適用する後埋め込みヒーター (c) 240 μ m 長い MEMS フィルターに高い直流電圧を適用する後埋め込みヒーター (b) 200 μ m 長い MEMS フィルターに適用する前に (、) 200 μ m 長い MEMS フィルター埋め込みヒーター。<a href="//cloudflare.jove.com/files/ftp_upload/56371/56371fig2large.jpg" target="_blank">この図の拡大版を表示するのにはここをクリックしてください</a>。
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/56371/56371fig3.jpg"> 図 3: モード形状。高次モード (モード-1 モード 9) ビーム<a href="//cloudflare.jove.com/files/ftp_upload/56371/56371fig3large.jpg" target="_blank">この図の拡大版を表示するのにはここをクリックしてください</a>。
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/56371/56371fig4.jpg"> 図 4: チューニング チューニング機能。別の関数として周波数応答とき 68 μ m 長い MEMS フィルター (、) の埋め込みヒーターにバイアス電圧を適用 Vdc = 25 V と Vac = 5 V、および (b) とき Vdc = 35 V と Vac この figur の拡大版を表示するのにはここを<a href="//cloudflare.jove.com/files/ftp_upload/56371/56371fig4large.jpg" target="_blank">してくださいクリックして対 1 を =e.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/56371/56371fig5.jpg"> 図 5: 高モード測定。(、) 測定高モード応答 L = 152 μ m 長い MEMS フィルター。同じモード形状と (b) の有限要素法によるシミュレーション結果。(c) 測定高次モード応答 L = 152 μ m 長い MEMS フィルターの異なる周波数で。<a href="//cloudflare.jove.com/files/ftp_upload/56371/56371fig5large.jpg" target="_blank">この図の拡大版を表示するのにはここをクリックしてください</a>。
<img alt="Figure 6" class="xfigimg" src="/files/ftp_upload/56371/56371fig6.jpg"> 図 6: 別のモードと予想される公演。MEMS フィルターに接続されている 1 の pg 質量を持つ最初のモードに関して (、) 正規化周波数のシフト。(b) 比較測定と 152 の高次モード応答 Coventor シミュレーション間 μ m 長い MEMS をフィルターします。<a href="//cloudflare.jove.com/files/ftp_upload/56371/56371fig6large.jpg" target="_blank">この図の拡大版を表示するのにはここをクリックしてください</a>。

Watch this Scientific Journal Video about Design and Characterization Methodology for Efficient Wide Range Tunable MEMS Filters at JoVE.com

Design and Characterization Methodology for Efficient Wide Range Tunable MEMS Filters

デザインと効率的な広帯域波長可変 MEMS フィルター特性評価手法

レーザドップラ (LDV) は、チューニング、チューニング機能、および装置の故障や、ヘッドス ライダーの回避の修正周波数測定などを用いた固定固定ビーム設計プロトコルが表示されます。その高いモード機能によりネットワーク アナライザーに LDV 法の優位性を発揮します。

Here, we demonstrate the advantages of the laser Doppler vibrometer (LDV) over conventional techniques (the network analyzer), as well as the techniques ...

design-characterization-methodology-for-efficient-wide-range-tunable

Nanyang Technological University

Research

JoVE Journal

Engineering

6.1K ビュー.  Harran University. レーザドップラ (LDV) は、チューニング、チューニング機能、および装置の故障や、ヘッドス ライダーの回避の修正周波数測定などを用いた固定固定ビーム設計プロトコルが表示されます。その高いモード機能によりネットワーク アナライザーに LDV 法の優位性を発揮します。

ビデオ: Design and Characterization Methodology for Efficient Wide Range Tunable MEMS Filters

Fabrication of Silica Ultra High Quality Factor Microresonators

Whispering gallery resonant cavities confine light in circular orbits at their periphery.1-2 The photon storage lifetime in the cavity, quantified by the quality factor (Q) of the cavity, can be in excess of 500ns for cavities with Q factors above 100 million. As a result of their low material losses, silica microcavities have demonstrated some of the longest photon lifetimes to date1-2. Since a portion of the circulating light extends outside the resonator, these devices can also be used to probe the surroundings. This interaction has enabled numerous experiments in biology, such as single molecule biodetection and antibody-antigen kinetics, as well as discoveries in other fields, such as development of ultra-low-threshold microlasers, characterization of thin films, and cavity quantum electrodynamics studies.3-7
The two primary silica resonant cavity geometries are the microsphere and the microtoroid. Both devices rely on a carbon dioxide laser reflow step to achieve their ultra-high-Q factors (Q&gt;100 million).1-2,8-9 However, there are several notable differences between the two structures. Silica microspheres are free-standing, supported by a single optical fiber, whereas silica microtoroids can be fabricated on a silicon wafer in large arrays using a combination of lithography and etching steps. These differences influence which device is optimal for a given experiment.
Here, we present detailed fabrication protocols for both types of resonant cavities. While the fabrication of microsphere resonant cavities is fairly straightforward, the fabrication of microtoroid resonant cavities requires additional specialized equipment and facilities (cleanroom). Therefore, this additional requirement may also influence which device is selected for a given experiment.
Introduction
An optical resonator efficiently confines light at specific wavelengths, known as the resonant wavelengths of the device. 1-2 The common figure of merit for these optical resonators is the quality factor or Q. This term describes the photon lifetime (&tau;o) within the resonator, which is directly related to the resonator's optical losses. Therefore, an optical resonator with a high Q factor has low optical losses, long photon lifetimes, and very low photon decay rates (1/&tau;o). As a result of the long photon lifetimes, it is possible to build-up extremely large circulating optical field intensities in these devices. This very unique property has allowed these devices to be used as laser sources and integrated biosensors.10
A unique sub-class of resonators is the whispering gallery mode optical microcavity. In these devices, the light is confined in circular orbits at the periphery. Therefore, the field is not completely confined within the device, but evanesces into the environment. Whispering gallery mode optical cavities have demonstrated some of the highest quality factors of any optical resonant cavity to date.9,11 Therefore, these devices are used throughout science and engineering, including in fundamental physics studies and in telecommunications as well as in biodetection experiments. 3-7,12
Optical microcavities can be fabricated from a wide range of materials and in a wide variety of geometries. A few examples include silica and silicon microtoroids, silicon, silicon nitride, and silica microdisks, micropillars, and silica and polymer microrings.13-17 The range in quality factor (Q) varies as dramatically as the geometry. Although both geometry and high Q are important considerations in any field, in many applications, there is far greater leverage in boosting device performance through Q enhancement. Among the numerous options detailed previously, the silica microsphere and the silica microtoroid resonator have achieved some of the highest Q factors to date.1,9 Additionally, as a result of the extremely low optical loss of silica from the visible through the near-IR, both microspheres and microtoroids are able to maintain their Q factors over a wide range of testing wavelengths.18 Finally, because silica is inherently biocompatible, it is routinely used in biodetection experiments.
In addition to high material absorption, there are several other potential loss mechanisms, including surface roughness, radiation loss, and contamination loss.2 Through an optimization of the device size, it is possible to eliminate radiation losses, which arise from poor optical field confinement within the device. Similarly, by storing a device in an appropriately clean environment, contamination of the surface can be minimized. Therefore, in addition to material loss, surface scattering is the primary loss mechanism of concern.2,8
In silica devices, surface scattering is minimized by using a laser reflow technique, which melts the silica through surface tension induced reflow. While spherical optical resonators have been studied for many years, it is only with recent advances in fabrication technologies that researchers been able to fabricate high quality silica optical toroidal microresonators (Q&gt;100 million) on a silicon substrate, thus paving the way for integration with microfluidics.1
The present series of protocols details how to fabricate both silica microsphere and microtoroid resonant cavities. While silica microsphere resonant cavities are well-established, microtoroid resonant cavities were only recently invented.1 As many of the fundamental methods used to fabricate the microsphere are also used in the more complex microtoroid fabrication procedure, by including both in a single protocol it will enable researchers to more easily trouble-shoot their experiments.

We describe the use of a carbon dioxide laser reflow technique to fabricate silica resonant cavities, including free-standing microspheres and on-chip microtoroids. The reflow method removes surface imperfections, allowing long photon lifetimes within both devices. The resulting devices have ultra high quality factors, enabling applications ranging from telecommunications to biodetection.

シリカ超高品質ファクターMicroresonatorsの作製

Whispering gallery resonant cavities confine light in circular orbits at their periphery.1-2 The photon storage lifetime in the cavity, quantified by the ...

工学

Terahertz Microfluidic Sensing Using a Parallel-plate Waveguide Sensor

Refractive index (RI) sensing is a powerful noninvasive and label-free sensing technique for the identification, detection and monitoring of microfluidic samples with a wide range of possible sensor designs such as interferometers and resonators 1,2. Most of the existing RI sensing applications focus on biological materials in aqueous solutions in visible and IR frequencies, such as DNA hybridization and genome sequencing. At terahertz frequencies, applications include quality control, monitoring of industrial processes and sensing and detection applications involving nonpolar materials.
Several potential designs for refractive index sensors in the terahertz regime exist, including photonic crystal waveguides 3, asymmetric split-ring resonators 4, and photonic band gap structures integrated into parallel-plate waveguides 5. Many of these designs are based on optical resonators such as rings or cavities. The resonant frequencies of these structures are dependent on the refractive index of the material in or around the resonator. By monitoring the shifts in resonant frequency the refractive index of a sample can be accurately measured and this in turn can be used to identify a material, monitor contamination or dilution, etc.
The sensor design we use here is based on a simple parallel-plate waveguide 6,7. A rectangular groove machined into one face acts as a resonant cavity (Figures 1 and 2). When terahertz radiation is coupled into the waveguide and propagates in the lowest-order transverse-electric (TE1) mode, the result is a single strong resonant feature with a tunable resonant frequency that is dependent on the geometry of the groove 6,8. This groove can be filled with nonpolar liquid microfluidic samples which cause a shift in the observed resonant frequency that depends on the amount of liquid in the groove and its refractive index 9.
Our technique has an advantage over other terahertz techniques in its simplicity, both in fabrication and implementation, since the procedure can be accomplished with standard laboratory equipment without the need for a clean room or any special fabrication or experimental techniques. It can also be easily expanded to multichannel operation by the incorporation of multiple grooves 10. In this video we will describe our complete experimental procedure, from the design of the sensor to the data analysis and determination of the sample refractive index.

The procedure for implementing a refractive index sensor for terahertz frequencies based on a grooved parallel-plate waveguide geometry is described here. The method yields a measurement of the refractive index of a small volume of liquid through monitoring of the shift in the resonant frequency of the waveguide structure

平行平板導波センサを用いたテラヘルツマイクロ流体センシング

Refractive index (RI) sensing is a powerful noninvasive and label-free sensing technique for the identification, detection and monitoring of microfluidic ...

Simulation, Fabrication and Characterization of THz Metamaterial Absorbers

Metamaterials (MM), artificial materials engineered to have properties that may not be found in nature, have been widely explored since the first theoretical1 and experimental demonstration2 of their unique properties. MMs can provide a highly controllable electromagnetic response, and to date have been demonstrated in every technologically relevant spectral range including the optical3, near IR4, mid IR5 , THz6 , mm-wave7 , microwave8 and radio9 bands. Applications include perfect lenses10, sensors11, telecommunications12, invisibility cloaks13 and filters14,15. We have recently developed single band16, dual band17 and broadband18 THz metamaterial absorber devices capable of greater than 80% absorption at the resonance peak. The concept of a MM absorber is especially important at THz frequencies where it is difficult to find strong frequency selective THz absorbers19. In our MM absorber the THz radiation is absorbed in a thickness of ~ &lambda;/20, overcoming the thickness limitation of traditional quarter wavelength absorbers. MM absorbers naturally lend themselves to THz detection applications, such as thermal sensors, and if integrated with suitable THz sources (e.g. QCLs), could lead to compact, highly sensitive, low cost, real time THz imaging systems.

This protocol outlines the simulation, fabrication and characterization of THz metamaterial absorbers. Such absorbers, when coupled with an appropriate sensor, have applications in THz imaging and spectroscopy.

テラヘルツメタマテリアルアブソーバのシミュレーション、作製と評価

Metamaterials (MM),  artificial materials engineered to have properties that may not be found in  nature, have been widely explored since the first ...

Implementation of a Reference Interferometer for Nanodetection

A thermally and mechanically stabilized fiber interferometer suited for examining ultra-high quality factor microcavities is fashioned. After assessing its free spectral range (FSR), the module is put in parallel with a fiber taper-microcavity system and then calibrated through isolating and eliminating random shifts in the laser frequency (i.e. laser jitter noise). To realize the taper-microcavity junction and to maximize the optical power that is transferred to the resonator, a single-mode optical fiber waveguide is pulled. Solutions containing polystyrene nanobeads are then prepared and flown to the microcavity in order to demonstrate the system&#8217;s ability to sense binding to the surface of the microcavity. Data is post-processed via adaptive curve fitting, which allows for high-resolution measurements of the quality factor as well as the plotting of time-dependent parameters, such as resonant wavelength and split frequency shifts. By carefully inspecting steps in the time-domain response and shifting in the frequency-domain response, this instrument can quantify discrete binding events.

A reference interferometer technique, which is designed to remove undesirable laser jitter noise for nanodetection, is utilized for probing an ultra-high quality factor microcavity. Instructions for assembly, setup, and data acquisition are provided, alongside the measurement process for specifying the cavity quality factor.

Nanodetectionのリファレンス干渉計の実装

A thermally and mechanically stabilized fiber interferometer suited for examining ultra-high quality factor microcavities is fashioned. After assessing ...

Real-Time DC-dynamic Biasing Method for Switching Time Improvement in Severely Underdamped Fringing-field Electrostatic MEMS Actuators

Mechanically underdamped electrostatic fringing-field MEMS actuators are well known for their fast switching operation in response to a unit step input bias voltage. However, the tradeoff for the improved switching performance is a relatively long settling time to reach each gap height in response to various applied voltages. Transient applied bias waveforms are employed to facilitate reduced switching times for electrostatic fringing-field MEMS actuators with high mechanical quality factors. Removing the underlying substrate of the fringing-field actuator creates the low mechanical damping environment necessary to effectively test the concept. The removal of the underlying substrate also a has substantial improvement on the reliability performance of the device in regards to failure due to stiction. Although DC-dynamic biasing is useful in improving settling time, the required slew rates for typical MEMS devices may place aggressive requirements on the charge pumps for fully-integrated on-chip designs. Additionally, there may be challenges integrating the substrate removal step into the back-end-of-line commercial CMOS processing steps. Experimental validation of fabricated actuators demonstrates an improvement of 50x in switching time when compared to conventional step biasing results. Compared to theoretical calculations, the experimental results are in good agreement.

The robust device design of fringing-field electrostatic MEMS actuators results in inherently low squeeze-film damping conditions and long settling times when performing switching operations using conventional step biasing. Real-time switching time improvement with DC-dynamic waveforms reduces the settling time of fringing-field MEMS actuators when transitioning between up-to-down and down-to-up states.

重度不足減衰フリンジフィールド静電MEMSアクチュエータに時間改善スイッチング用リアルタイムDC-ダイナミックバイアス方式

Mechanically underdamped electrostatic fringing-field MEMS actuators are well known for their fast switching operation in response to a unit step input ...

Fabrication and Testing of Microfluidic Optomechanical Oscillators

Cavity optomechanics experiments that parametrically couple the phonon modes and photon modes have been investigated in various optical systems including microresonators. However, because of the increased acoustic radiative losses during direct liquid immersion of optomechanical devices, almost all published optomechanical experiments have been performed in solid phase. This paper discusses a recently introduced hollow microfluidic optomechanical resonator. Detailed methodology is provided to fabricate these ultra-high-Q microfluidic resonators, perform optomechanical testing, and measure radiation pressure-driven breathing mode and SBS-driven whispering gallery mode parametric vibrations. By confining liquids inside the capillary resonator, high mechanical- and optical- quality factors are simultaneously maintained.

Parametric optomechanical excitations have recently been experimentally demonstrated in microfluidic optomechanical resonators by means of optical radiation pressure and stimulated Brillouin scattering. This paper describes the fabrication of these microfluidic resonators along with methodologies for generating and verifying optomechanical oscillations.

作製とマイクロ流体光力学発振器のテスト

Cavity optomechanics experiments that parametrically couple the phonon modes and photon modes have been investigated in various optical systems including ...

Using Micro-Electro-Mechanical Systems (MEMS) to Develop Diagnostic Tools

Using Micro-Electro-Mechanical Systems MEMS to Develop Diagnostic Tools

I'm U De Mercy, I'm the principal investigator of Bio Stick MAMs in Medicine Labs. I did my PhD at Stanford University in electrical engineering. I did a postdoc at Harvard Medical School at MGH working on bio acoustic MAMs or mostly bio MAs.And now I'm continuing as a faculty at Harvard Medical School at Harvard MIT Health Sciences and Technology. And continuing with my research that I enjoy very much. The work that I did during my PhD was very much related to droplets and using acoustics to generate precise size droplets and control their location and position to deposit very sensitive polymers.Now we apply similar technologies to encapsulate cells in droplets and then position them on the surfaces for various applications in tissue engineering to print cells on the surfaces to pattern cells. Also, there are applications where you want to see that you can encapsulate few cells or a single cell or from the same population and to see the differences between the same population from one cell to another there being able to encapsulate cells in droplets at high throughput rates like 10, 000 cells per second kind of rates becomes very important and very useful to understand biological problems. So my research currently has two legs, I would say.One is this cell encapsulation work that I just talked about. How do we pack a cell in a droplet that's, and how can we do this repeatedly and reliably and without harming the cells? So after the cell is ejected or encapsulated in the droplet, we should be able to precisely located on a surface the cell should be functional and alive and viable.It shouldn't be harmed by the effects of ejection and so forth. So currently we have a system where we use acoustic drop focused waves to generate these droplets from open pools where we can encapsulate down to single cells in these really small droplets that are comparable to the cell size. That's very exciting in terms of applying this to cell printing and tissue engineering.The other side of my research is again using these MAMs micro electromechanical system technologies to develop low cost diagnostic tools. Mostly this research uses microfluidic approaches where we can introduce whole blood, very small volumes such as blood from a prick finger prick, less than 10 microliters that you can introduce to a chip. And from that blood we can encapsulate or you can capture certain sub-cellular populations from whole blood.Why is this important? Why should this be cheap for global health applications On top of the mountain in Africa, you want to be able to tell for a HIV patient, for instance, how many CD four T lymphocytes this patient has. Because World Health Organization says that below 200 CD four cells per microliter, you have to start treating the patients In the developed world, you use hundreds of thousands dollars of vert flow cytometers to be able to get this data.And it takes of course time to use and skill of course to be able to use these like huge table size machines. Our small chip can be introduced this small finger brick 10 microliters of whole blood and it'll capture the CD four cells using the surface protein affinities. And then you can rapidly count these cells that are captured because you know that there are CD four cells which are attached to CD four proteins antibodies on the surface of the chip.By controlling the flow rates and shear, you can make sure that the specificity and efficiency for these cell types are optimized. And there's of course always non specific binding, but by our sheer approaches we minimize these effects and make sure that between plus minus 10%errors, which is sufficient to make a diagnostic or prognostic decision on top mountain in Africa. So this has interesting applications for global health as well as these low cost techniques that are disposable can impact the developed world because now these fast blood tests which are really low cost can impact the tests that we use in the developed world.If they're optimized to higher levels of efficiency and specificity, which our initial data shows that they can be, then it'll definitely impact our lives. When I first finished my PhD, I knew more about microfluidics and that in MAMs more than anything else I could see, especially with the droplet application, I could see that if I could print cells and encapsulate cells or manipulate the few cells, single cells, that it'll have great applications in biotechnology area. And I was very interested in working on things that will actually impact people's lives.I used to apply these technologies to semiconductor industry, but then I wanted to to be useful directly to people. So I, that's what directed me towards problems in healthcare. And then that's why I made a big shift and came to a hospital, mass general hospital to the postdoc.And there, you know, I got exposed more and more to problems and it seems, and it's all clear that one of the biggest problems of the world today is global health and there comes illnesses like tuberculosis, HIV that kills thousands of people per day. And these people die not because the drugs are not there, but because there aren't enough diagnostic tools which is much more expensive than the existing drugs. So I know the technology side of the things very well.I get, I got exposed to the biological problems and the more I learned about them, the more I could see that I could make an impact. And that's how it all grew from there. And it's still continuing now.Like I seen biotechnology and in medicine there are like so many problems that actually directly cause our result into loss of people's lives and the technologies, the technology aspect of it and being able to apply it to real world medical problems is a great, I think path to follow. This is like how this whole biotechnology area I think is kind of growing and it's becoming very impactful. If you think about it, HIV cancer, those are big killers in the world.And current micro technologies, current approaches could maybe benefit from early detection of cancer by capturing these cells from blood or making it really cheap, which will make it available to masses. So all these things coming together, I think this whole microtechnology applications in healthcare in medicine could impact the future of human beings. So that's how all these things kind of come together I guess.And being in the Harvard MIT health sciences and technology where on one end you have the technology and on the other end you direct aspect, direct access to patients, direct access to doctors in Brigham and Women's Hospital where I work is a great environment. cause every person that you talk to have their problems and you could maybe it's coming from a different background, provide interesting solutions to those existing real world problems. So this is, I think how I see the whole perspective of how these medical problems meet the technology side.And we try to impact people's lives in a positive way. In single cell cap encapsulation or in cell encapsulation, the major challenge is to be able to encapsulate reliably and repeatably single cells. So you're ejecting 10, 000 hundred thousand cells per second.And how do you make sure that each droplet that you eject has a single cell? This statistics where you are changing the droplet size and minimizing the, optimizing the cell size over the droplet size, which goes into the old problem of packing spheres in a volume and what is the most efficient way to do it. So that's the biggest challenge in the cell printing area for from the technological side.The other aspect of it is now you can say print and precisely locate these cells. How can you generate these three dimensional tissues and how can you keep them alive and how can you transplant them? There comes in the biological end of the problems where you want to now exactly mimic the tissue.We have current approaches to be able to print an eyelet, a pancreas eyelet, and to be able to print using smooth muscle cells, a bladder tissue, directly mimicking what is in human or red bladder so that then we can make this tissue and test how well it performs compared to the real world existing native tissues. So that's the major challenge I guess by taking these novel technologies, how can you make this the ideal tissue that can be replaced, that can be transplanted, that's the, you know, biggest problem from the beginning because the control on single cell gives you the capability to precisely locate them. And then how do you kind of grow it from there?So it's something transplantable there where the impact of human life comes. So that's on that end, what the challenges are in the tissue engineering side of the things in southern encapsulation and in diagnostics using microfluidics, the challenge is to be able to capture a cell out of billions of cells. It's like you have a sugar particle in a salt can and you're trying to pull out that sugar particle and that's like one in a billion.So you, you're processing microliters to milliliters of whole blood and you want to be able to specifically and efficiently without any technological problems like clogging or any biological problems like non-specific binding, you want to be able to isolate at one cell out of billion cells in one microliter of whole blood, you have a few millions of cells. And for the CD four T lymphocyte case in that one microliter, we are after about thousand cells per microliter. So it's like one cell in a thousand kind of a problem where we have shown that it's doable.But when you want to go after circulating tumor cells for cancer, then the challenge becomes one in a billion. So to some summarize it, the challenge is how do we capture this one cell out of billions of other cells around it? And what is the technological aspects?What are the flow rates? What is the device design? What, what are the flow rates?What, what are the volumes of blood that has to be processed and how do you make sure that the cells you capture are the ones that you actually wanted to capture? All these aspects kind formed the whole challenge that can be summarized in one sentence, which is how do you capture this one rare cell out of billion others? So it's really a needle in a haystack kind of problem, which is exciting.And I think this is moving the technologies forward to address these problems is the current technological challenge. Being able to bring them to a level where they do the job that they're supposed to do is one thing. And then taking it to the clinic and making it a product has all different expertise such as being able to start a company, being able to patent these things and all those other aspects come into the picture.And I think we as scientists primarily don't have all of those skills that takes the products from desktop to products. So there comes in again, the importance of collaborations with people who have different backgrounds. And there are many technologies out there that I think could be very impactful and useful.They sometimes don't make it to the clinic or to the use of humankind either because it just didn't happen, wasn't the right time or other effects came into the picture that I just talked about. Or sometimes there isn't a direct link that you couldn't see that the technology could actually solve that problem. And the person who deals with the problem, or let's say the biologists or people in medicine are used to doing it one way for many years.And the people on the technology side mostly if you're not having a biotechnology focus, are not aware of the problems in medicine. So bringing these two sides together is a serious interdisciplinary research. And I think in the past years, the whole emphasis both at NIH level and that we see in research labs and universities is to generate interdisciplinary research.So people end up getting PhDs where they have to know multiple fields. For instance, for my PhD, I had to know acoustics, I had to know mems, I had to know microfluidics and I had to apply this for polymers. So now you see kinda very depth of knowledge in one field where you had to know actually three other fields quite well to be able to solve that problem.So I think the answer is in interdisciplinary research combined with people with business skills to make it available to use of the people, it's a whole big process and some inefficiencies that come in at certain locations. Cause that low percent of tech transfer.

診断ツールを開発するマイクロエレクト​​ロメカニカルシステム（MEMS）の使用

生物学

Compact Lens-less Digital Holographic Microscope for MEMS Inspection and Characterization

A micro-electro-mechanical-system (MEMS) is a widely used component in many industries, including energy, biotechnology, medical, communications, and automotive. However, effective inspection and characterization metrology systems are needed to ensure the functional reliability of MEMS. This study presents a system based on digital holography as a tool for MEMS metrology. Digital holography has gained increasing attention in the past 20 years. With the fast development and decreasing cost of sensor arrays, resolution of such systems has increased broadening potential applications. Thus, it has attracted attention from both research and industry sides as a potential reliable tool for industrial metrology. Indeed, by recording the interference pattern between an object beam (which contains sample height information) and a reference beam on a CCD camera, one can retrieve the quantitative phase information of an object. However, most of digital holographic systems are bulky and thus not easy to implement on industry production lines. The novelty of the system presented is that it is lens-less and thus very compact. In this study, it is shown that the Compact Digital Holographic Microscope (CDHM) can be used to evaluate several characteristics typically consider as criteria in MEMS inspections. The surface profiles of MEMS in both static and dynamic conditions are presented. Comparison with AFM is investigated to validate the accuracy of the CDHM.

We present a compact reflection digital holographic system (CDHM) for inspection and characterization of MEMS devices. A lens-less design using a diverging input wave providing natural geometrical magnification is demonstrated. Both static and dynamic studies are presented.

MEMS検査および特性評価のためのコンパクトなレンズレスデジタルホログラフィック顕微鏡

A micro-electro-mechanical-system (MEMS) is a widely used component in many industries, including energy, biotechnology, medical, communications, and ...

Fabrication and Characterization of Superconducting Resonators

Superconducting microwave resonators are of interest for a wide range of applications, including for their use as microwave kinetic inductance detectors (MKIDs) for the detection of faint astrophysical signatures, as well as for quantum computing applications and materials characterization. In this paper, procedures are presented for the fabrication and characterization of thin-film superconducting microwave resonators. The fabrication methodology allows for the realization of superconducting transmission-line resonators with features on both sides of an atomically smooth single-crystal silicon dielectric. This work describes the procedure for the installation of resonator devices into a cryogenic microwave testbed and for cool-down below the superconducting transition temperature. The set-up of the cryogenic microwave testbed allows one to do careful measurements of the complex microwave transmission of these resonator devices, enabling the extraction of the properties of the superconducting lines and dielectric substrate (e.g., internal quality factors, loss and kinetic inductance fractions), which are important for device design and performance.

Superconducting microwave resonators are of interest for detection of light, quantum computing applications and materials characterization. This work presents a detailed procedure for fabrication and characterization of superconducting microwave resonator scattering parameters.

超伝導共振器の作製と評価

Superconducting microwave resonators are of interest for a wide range of applications, including for their use as microwave kinetic inductance detectors ...

Microparticle Manipulation by Standing Surface Acoustic Waves with Dual-frequency Excitations

We demonstrate a method for increasing the tuning ability of a standing surface acoustic wave (SSAW) for microparticles manipulation in a lab-on-a-chip (LOC) system. The simultaneous excitation of the fundamental frequency and its third harmonic, which is termed as dual-frequency excitation, to a pair of interdigital transducers (IDTs) could generate a new type of standing acoustic waves in a microfluidic channel. Varying the power and the phase in the dual-frequency excitation signals results in a reconfigurable field of the acoustic radiation force applied to the microparticles across the microchannel (e.g., the number and location of the pressure nodes and the microparticle concentrations at the corresponding pressure nodes). This article demonstrates that the motion time of the microparticle to only one pressure node can be reduced ~2-fold at the power ratio of the fundamental frequency greater than ~90%. In contrast, there are three pressure nodes in the microchannel if less than this threshold. Furthermore, adjusting the initial phase between the fundamental frequency and the third harmonic results in different motion rates of the three SSAW pressure nodes, as well as in the percentage of microparticles at each pressure node in the microchannel. There is a good agreement between the experimental observation and the numerical predictions. This novel excitation method can easily and non-invasively integrate into the LOC system, with a wide tenability and only a few changes to the experimental set-up.

A protocol for manipulating the microparticles in a microfluidic channel with a dual-frequency excitation is presented.

立って二周波励起表面波による微小物体操作

We demonstrate a method for increasing the tuning ability of a standing surface acoustic wave (SSAW) for microparticles manipulation in a lab-on-a-chip ...

デザインと効率的な広帯域波長可変 MEMS フィルター特性評価手法

要約

さらに動画を探す

シリカ超高品質ファクターMicroresonatorsの作製

平行平板導波センサを用いたテラヘルツマイクロ流体センシング

テラヘルツメタマテリアルアブソーバのシミュレーション、作製と評価

Nanodetectionのリファレンス干渉計の実装

重度不足減衰フリンジフィールド静電MEMSアクチュエータに時間改善スイッチング用リアルタイムDC-ダイナミックバイアス方式

作製とマイクロ流体光力学発振器のテスト

診断ツールを開発するマイクロエレクトロメカニカルシステム（MEMS）の使用

MEMS検査および特性評価のためのコンパクトなレンズレスデジタルホログラフィック顕微鏡

超伝導共振器の作製と評価

立って二周波励起表面波による微小物体操作

デザインと効率的な広帯域波長可変 MEMS フィルター特性評価手法

要約

さらに動画を探す

シリカ超高品質ファクターMicroresonatorsの作製

平行平板導波センサを用いたテラヘルツマイクロ流体センシング

テラヘルツメタマテリアルアブソーバのシミュレーション、作製と評価

Nanodetectionのリファレンス干渉計の実装

重度不足減衰フリンジフィールド静電MEMSアクチュエータに時間改善スイッチング用リアルタイムDC-ダイナミックバイアス方式

作製とマイクロ流体光力学発振器のテスト

診断ツールを開発するマイクロエレクト​​ロメカニカルシステム（MEMS）の使用

MEMS検査および特性評価のためのコンパクトなレンズレスデジタルホログラフィック顕微鏡

超伝導共振器の作製と評価

立って二周波励起表面波による微小物体操作

診断ツールを開発するマイクロエレクトロメカニカルシステム（MEMS）の使用