時間分解赤外振動分光測定の東京工科大学の博士田中と原正憲教授と x 線回折測定のため名古屋大学松尾和人博士に感謝します名古屋大学、キール大学教授 r. Herges 教授 r. j. D. ミラー構造のマックス ・ プランク研究所と物質ダイナミクス貴重な議論のために山口悟先生もありがちましょう。
この作品は日本科学技術 (JST) によってをさきがけ「分子技術と新機能創出」プロジェクトの資金調達のためサポートされて (JPMJPR13KD、JPMJPR12K5、および JPMJPR16P6 の付与数) と「光エネルギーの化学的変換」。この作品は、日本学術振興会助成番号 JP15H02103、JP17K17893、JP15H05482、JP17H05258、JP26107004、および JP17H06375 によっても部分的にサポートされます。

1.Time 分解赤外振動分光法
<ol><li>
サンプル準備
	<ol>
<li>解決方法: は、シクロオクタテトラエンの π 拡張 (π COT) 分子を適切な濃度 (1 モル/L) でジクロロ メタンに溶解します。</li>
		<li>液晶相: 100 ° C の温度でホット プレートを用いたフッ化カルシウム (CaF2) 基板上 π ベビーベッド粉末を溶かす室温でサンプルを冷却します。 注: 我々 は中赤外範囲の透明マテリアル (CaF2またはバリウム フッ化 (BaF2)) を選択する必要があります。</li>
	</ol>
</li>
	<li>
装置の設定
	<ol>
<li>チタン サファイア (チタンサファイアレーザー) レーザーのチャープ パルス増幅器を切り替えます。熱いくつかの時間のためにそれらを安定させます。</li>
		<li>アライメントが正しいかどうかを確認します。電源と紫外線 (UV) ポンプと中赤外プローブの安定性を確認し、必要に応じて光パスを再調整。時間分解赤外分光法の光のセットアップは図 5で提供されます。</li>
		<li>液体窒素を用いてについて IR 検出器を冷却します。利息の範囲で光の合理的な量が検出されたので、分光計が正しく置かれていることを確認します。ポリスチレンやポリエチレン テレフタ レートなどよく知られている材料の吸収スペクトルを用いた分光器を調整します。</li>
		<li>サンプル ホルダーに大規模な光誘起過渡応答 (Si ウェハ (1 mm) または Re(bpy)(CO)3Cl/CH3CN ソリューション) を示すサンプルをマウントします。ポンプ-プローブ遅延に正の値を検索し、攪拌ポンプ ・ プローブの重なりを確保するためポンプ光による非定常信号の量を最適化します。</li>
		<li>自作プログラム (図 6) を使用して、ポンプ ・ プローブ遅延に長距離スキャンすることによって時間の元の設定を見つけます。過渡信号が出現する開始位置を確認します。</li>
		<li>CO Re(bpy)(CO)3Cl が双極子モーメントが直交でストレッチの対称・反対称振動のダイナミクスをチェックします。マジック角条件が正しく満たされる同じダイナミクスを示す両方する必要がありますに注意してください。</li>
	</ol>
</li>
	<li>
測定およびデータ集録
	<ol>
<li>解決方法: マウント自作フローセル。必要に応じて不活性ガス (アルゴン (Ar) や窒素 (N2)) とバブル デバイスをセットアップします。液晶相: レーザ誘起損傷を最小限に抑えるためのサンプルにレーザー スポットを連続的に移動するモーターを備えられた段階で基板と π ベビーベッドをスピン コーティング サンプルをマウントします。</li>
		<li>抜きなさいサンプルに時間ゼロの位置。</li>
		<li>ポンプ-プローブ遅延スキャン範囲を正しく設定 (開始、終了、およびステップ)。</li>
		<li>データを保存するディレクトリを選択します。</li>
		<li>自作プログラムとデータの収集を開始します。 注意: データは、ディレクトリに自動的に記録されます。</li>
	</ol>
</li>
</ol>2. 時間分解電子回折法
<ol><li>
サンプル基板の作製
	<ol>
<li>購入を両側があらかじめ厚 30 nm シリコンの豊富なケイ素 (Si3N4、または単に罪) で覆われているシリコン (001) ウェーハ (200 μ m 厚)、映画 (図 11A)。広場 (15 × 15 mm2) の罪/Si ウエハをカットします。</li>
		<li>Ar クラスター イオン ビーム41 2.5 × 1016イオン/cm2に罪/Si ウェハの側面の 1 つのフルエンスで照射も金属マスク (図 12)、30 nm 厚の罪映画 (図 11 を削除するのに十分であります。 B、C)。 注: SiN 膜を削除する別の方法は、プラズマ エッチングまたはイオンビーム エッチング。</li>
		<li>28% の濃度の水酸化カリウム (KOH) 水溶液を準備します。</li>
		<li>1-2 日 (図 11D) 60-70 ° C の温度下での KOH 溶液にウェハを入れてさらに等方性化学42をエッチングによる Si ウエハのエッチングを行う。 注: KOH 溶液によるシリコンのエッチング速度は罪の薄膜が自立膜 (図 11E) として残っているので、罪のためのそれよりもはるかに高速です。</li>
		<li>脱イオン水で罪膜ウェーハをクリーンし、窒素ガスで乾燥します。</li>
	</ol>
</li>
	<li>
サンプル準備
	<ol>
<li>10 mg/mL の濃度のクロロホルムで π ベビーベッド分子を分解します。</li>
		<li>スピンコーターをプログラム: 5 で 2000 rpm の加速 s、30 s、および停止回転の回転を維持します。スピンコート罪膜基板図 11Fのように π ベビーベッド ソリューション。 注: スピン コーティングの適切なウェーハ サイズは 10 × 10 mm 以上にする必要があります2、時々 は表面張力はたとえば小さい基板材料のスピン コーティングと干渉するので、透過電子顕微鏡用罪膜グリッド。</li>
		<li>100 ° C の高温ホット プレートに罪膜基板上にコーティング サンプルを入れて、それを溶かす室温 (図 11G) にそれを徐々 に冷却します。</li>
	</ol>
</li>
	<li>
測定
	<ol>
<li>サンプルをサンプル ホルダーのネジでマウントし、試料ホルダーを入れて真空チャンバー (試料室)。</li>
		<li>真空チャンバー内にふたを密封し、1000 未満の真空レベルまで部屋を避難するロータリー ポンプのスイッチ ペンシルバニア州〜 10-6 Pa (通常は 12 時間以上) の真空のレベルでは、電子銃室まで、ターボ分子ポンプに切り替えます。</li>
		<li>チタンサファイアレーザー レーザーのチャープ パルス増幅器、スイッチ、熱 1 h 以上のそれらを安定します。時間分解電子回折の実験装置は、図 9に提供しています。繰り返しレートを 500 Hz に設定します。</li>
		<li>電荷結合素子 (CCD) カメラのスリラーに切り替え、10 ° C に冷却</li>
		<li>電力供給に切り替えるし、75 に電圧を調整する kV。 メモ: 電源装置のリーク電流 0.1 μ A 範囲外変動しません。</li>
		<li>特別なオーバー ラップ。研究所コードの自動プログラム (図 10A) を開き、露出時間 (50 ミリ秒) を設定します。Z 軸と Y_overlap と押すとスタートボタンの重複起動の種類をZ_overlapに設定してプログラムを使用してサンプル ホルダーに装備したピンホールを持つ電子ビーム位置を検索します。</li>
		<li>ピンホールの位置に電子ビームを設定し、ピンホールによって反射したポンプ光を用いたポンプ レーザを揃えます。</li>
		<li>押すと時分割するスタートアップの種類の設定によって研究所コードの自動プログラム (図 10のB) を使用してサンプル ホルダーの無機材料 (Bi2テ3) 時間ゼロ位置を測定します。ボタンを開始します。このプロセスの 2 mJ/cm2にポンプ流量を調整します。</li>
		<li>電子ビームのパスにファラデーカップを挿入し、電子ビーム研究所製 picoammeter とのフルエンスを測定、プローブ行に調整可能な ND フィルターを回転させることにより調整。ポンプ線波長板を回転させることによりポンプ パルスの thefluence を調整します。</li>
		<li>サンプル位置に移動し、CCD カメラの露光時間を設定します。単にスタートアップの種類を設定し、スタートボタンを押すと研究所コードの自動プログラム (図 10B) を使用して電子回折像を得る。</li>
		<li>CCD カメラのペルチェ素子に切り替え、-20 ° C の温度まで冷却</li>
		<li>時間ステップの設定と時間分解測定のステップ数。時間解決する開始の種類を設定し、スタートボタンを押すと研究所コードの自動プログラム (図 10B) を用いた時間分解電子回折画像を取得します。</li>
		<li>時間解決する開始の種類を設定することによって電子加速電源研究所コードの自動プログラム (図 10のB) を使用してオフに時間分解背景画像を取得し、スタートボタンを押します。</li>
	</ol>
</li>
</ol>

著者が明らかに何もありません。

時間分解電子回折測定中のプロセスの重要なステップは、高電圧を維持する (75 keV) 光電陰極と陽極間の距離から電流揺らぎなしプレートは ~ 10 mm のみ。0.1 μ A の範囲を超える変動前に、または実験中、増加最大 90 加速電圧に放電し、再度 75 に設定 keV keV。このコンディショニング過程は、0.1 μ A の範囲の電流が変動するまでに行う必要があります。十分な絶縁耐力を持つ電子源の適切な設?...

液晶 (LCs) は、多彩な機能を有し、科学的および技術アプリケーション1,2,3,4,5,6で広く使用されています。LCs の動作は、分子の高移動度に関しても配向順序に帰することができます。液晶材料の分子構造は通常高分子コアと液晶分子の高い機動性を確保する柔軟な長い炭素鎖によって特徴付けられます。外部刺激7,8,9,10、11,12,13,14,15、ライト、電界、温度変化、または機械的圧力で小さな内およびその機能的な動作につながるシステムの並べ替え LC 分子原因抜本的な構造の分子間運動など。液晶材料の機能を理解するには、液晶相の分子スケール構造を判断し、有機分子のコンフォメーションとパッキンの変形のキーの動きを識別することが重要です。
X 線回折 (XRD) は LC 材料16,17,18の構造を決定するための強力なツールとして一般的です。ただし、機能刺激応答性コアから発信された回折パターンは多くの場合、長い炭素鎖から広範なハロー パターンによって隠されます。この問題への効果的なソリューションは、光励起を用いた分子動力学の直接観察を可能にする時間分解回折によって提供されます。この手法は、光励起後で得た回折パターンの違いを使用して光の芳香環の構造に関する情報を抽出します。これらの違いは、バック グラウンド ノイズを除去して興味の構造の変化を直接観測する手段を提供します。差分の回折パターンの解析では、単独で、それにより非光応答性の炭素鎖から有害な回折を除く光活性部位から変調信号を明らかにします。羽田雅ら19はこの差分回折分析方法の説明です。
時間分解回折測定材料20,21,22,23,の相転移時に発生する原子の再配列構造情報を提供します。24,25,26,27,28,29化学反応と分子30,31,32,33,34の間で。念頭に置いてこれらの用途で顕著な進展した超高輝度・超短パルス x 線35,36 ・電子37,38,39の開発に,40ソース。しかし、時間分解回折のみで適用されているシンプルな孤立した分子またはするまたはポリ-結晶、高無機格子を発注または有機分子構造を提供するよく解決された回折パターンを生成情報。対照的に、その少ない秩序相のためより複雑なソフトマテリアルの超高速構造解析が妨げられています。本研究で我々 は時間分解電子回折と同様過渡吸収分光およびこれを用いた光の LC 材料の構造ダイナミクスを特徴付ける時間分解赤外 (IR) 振動分光法の使用方法を示す回折抽出方法論19。

<table><tbody><tr><td>Chirped pulse amplifier</td><td>Spectra Physics Inc.</td><td>Spitfire ACE</td><td>For time-resolved IR vibration spectroscopy</td></tr><tr><td>Chirped pulse amplifier&amp;nbsp;</td><td>Spectra Physics Inc.</td><td>Spitfire XP</td><td>For time-resolved electron diffractometry</td></tr><tr><td>Femtosecond laser</td><td>Spectra Physics Inc.</td><td>Tsunami</td><td>For time-resolved IR vibration spectroscopy</td></tr><tr><td>Femtosecond laser</td><td>Spectra Physics Inc.</td><td>Tsunami</td><td>For time-resolved electron diffractometry</td></tr><tr><td>Optical parametric amplifier</td><td>Light Conversion Ltd.</td><td>TOPAS prime</td><td></td></tr><tr><td>64-channel mercury cadmium tellurium IR detector array</td><td>Infrared Systems Development Corporation</td><td>FPAS-6416-D</td><td></td></tr><tr><td>FT-IR spectrometer</td><td>Shimadzu Corporation</td><td>IR Prestige-21</td><td></td></tr><tr><td>High voltage supply</td><td>Matsusada precision</td><td>HER-100N0.1</td><td></td></tr><tr><td>Rotary pump</td><td>Edwards</td><td>RV12</td><td></td></tr><tr><td>Molecular turbo pumps</td><td>Agilent Technologies Japan, Ltd.</td><td>Twis Torr 304FS</td><td></td></tr><tr><td>Vacuum gauges</td><td>Pfeiffer vacuum systems gmbh</td><td>PKR251</td><td>For ICF70 flange</td></tr><tr><td>Vacuum monitors</td><td>Pfeiffer vacuum systems gmbh</td><td>TPG261</td><td></td></tr><tr><td>Fiber coupled CCD camera</td><td>Andor Technology Ltd.</td><td>iKon-L HF</td><td></td></tr><tr><td>BaF2 and CaF2 substrates</td><td>Pier optics</td><td></td><td>Thickness 3 mm</td></tr><tr><td>AgGaS2 crystal</td><td>Phototechnica Corporation</td><td></td><td>Custom-order</td></tr><tr><td>BBO crystals</td><td>Tokyo Instruments, Inc.</td><td></td><td>SHG &amp;theta;=29.2 deg&lt;br/&gt; THG &amp;theta;=44.3 deg</td></tr><tr><td>calcite crystals</td><td>Tokyo Instruments, Inc.</td><td></td><td>Thickness 1mm</td></tr><tr><td>Optical mirrors</td><td>Thorlabs</td><td>PF10-03-F01&lt;br/&gt; PF10-03-M01&lt;br/&gt; UM10-45A</td><td>Al coat mirrors&lt;br/&gt; Au coat mirrors&lt;br/&gt; Ultrafast mirrors</td></tr><tr><td>Optical mirrors</td><td>HIKARI,Inc.</td><td></td><td>Broadband mirrors</td></tr><tr><td>Dichroic mirrors</td><td>HIKARI,Inc.</td><td></td><td>Custom-order&lt;br/&gt; Reflection: 266 nm&lt;br/&gt; Transmission: 400, 800 nm</td></tr><tr><td>Optical chopper</td><td>Newport Corporation</td><td>3501 optical chopper</td><td></td></tr><tr><td>Optical shutters</td><td>Thorlabs Inc.</td><td>SH05/M&lt;br/&gt; SC10</td><td></td></tr><tr><td>Optical shutters</td><td>SURUGA SEIKI CO.,LTD.</td><td>F116-1</td><td></td></tr><tr><td>Beam splitters</td><td>Thorlabs Inc.</td><td>BSS11R</td><td></td></tr><tr><td>Fused-silica lenses</td><td>Thorlabs Inc.</td><td>LA4663&lt;br/&gt; LA4184</td><td></td></tr><tr><td>BaF2 lens</td><td>Thorlabs Inc.</td><td>LA0606-E</td><td></td></tr><tr><td>Polarized mirrors</td><td>Sigmakoki Co.,Ltd</td><td></td><td>Custom-order&lt;br/&gt; Designed for 800 nm&lt;br/&gt; Reflection: s-polarized light&lt;br/&gt; Transmission : p-polarized light</td></tr><tr><td>Half waveplate</td><td>Thorlabs Inc.</td><td>WPH05M-808</td><td></td></tr><tr><td>Mirror mounts</td><td>Thorlabs Inc.</td><td>POLARIS-K1&lt;br/&gt; KM100</td><td>Kinematic mirror mounts</td></tr><tr><td>Mirror mounts</td><td>Sigmakoki Co.,Ltd</td><td>MHAN-30M&lt;br/&gt; MHAN-30S</td><td>Gimbal mirror mounts</td></tr><tr><td>Mirror mounts</td><td>Newport Corporation</td><td>ACG-3K-NL</td><td>Gimbal mirror mounts</td></tr><tr><td>Variable ND filters</td><td>Thorlabs Inc.</td><td>NDC-25C-2M</td><td></td></tr><tr><td>Beam splitter mounts</td><td>Thorlabs Inc.</td><td>KM100S</td><td></td></tr><tr><td>Lens mounts</td><td>Thorlabs Inc.</td><td>LMR1/M</td><td></td></tr><tr><td>Rotational mounts</td><td>Thorlabs Inc.</td><td>RSP1/M</td><td></td></tr><tr><td>Retroreflector</td><td>Edmund Optics</td><td>63.5MM X 30&quot; EN-AL&amp;nbsp;</td><td></td></tr><tr><td>spectrometers</td><td>ocean photonics</td><td>USB-4000</td><td></td></tr><tr><td>Power meter</td><td>Ophir</td><td>30A-SH</td><td>Used for intensity monitor of CPA</td></tr><tr><td>Power meter</td><td>Thorlabs Inc.</td><td>S120VC&lt;br/&gt; PM100USB</td><td>Used for intensity measurements of pump pulse</td></tr><tr><td>Photodiodes</td><td>Thorlabs Inc.</td><td>DET36A/M&lt;br/&gt; DET25K/M</td><td></td></tr><tr><td>DC power supply</td><td>TEXIO</td><td>PW18-1.8AQ</td><td>Used for magnetic lens</td></tr><tr><td>Magnetic lens</td><td>Nissei ETC Co.,Ltd</td><td></td><td>Custom-order</td></tr><tr><td>Stages</td><td>Newport Corporation</td><td>M-MVN80V6&lt;br/&gt; LTAHLPPV6</td><td>Used for magnetic lens</td></tr><tr><td>Stage controller</td><td>Newport Corporation</td><td>SMC100</td><td></td></tr><tr><td>Stages&amp;nbsp;</td><td>Sigmakoki Co.,Ltd</td><td>SGSP20-35(X)&lt;br/&gt; SGSP20-85(X)</td><td>Used for sample position</td></tr><tr><td>Stages&amp;nbsp;</td><td>Sigmakoki Co.,Ltd</td><td>SGSP26-200(X)&lt;br/&gt; OSMS26-300(X)</td><td>Used for delay time generator</td></tr><tr><td>Stage controller</td><td>Sigmakoki Co.,Ltd</td><td>SHOT-304GS</td><td></td></tr><tr><td>Picoammeter</td><td></td><td></td><td>Laboratory built</td></tr><tr><td>spin coater</td><td>MIKASA Co.,Ltd</td><td>1H-D7</td><td></td></tr><tr><td>hot plate</td><td>IKA&amp;reg;&amp;nbsp;</td><td>C-MAG HP7</td><td></td></tr><tr><td>SiN wafer</td><td>Silson Ltd</td><td></td><td>Custom-order</td></tr><tr><td>KOH aqueous solution (50%)</td><td>Hiroshima Wako Co.,Ltd.</td><td>168-20455</td><td></td></tr><tr><td>Chloroform</td><td>Hiroshima Wako Co.,Ltd.</td><td>038-18495</td><td></td></tr><tr><td>Dichloromethane</td><td>Hiroshima Wako Co.,Ltd.</td><td>132-02456</td><td></td></tr><tr><td>Personal computers for the controlling programs</td><td>Epson Corporate</td><td>Endeavor MR7300E-L</td><td>32-bit operation system</td></tr><tr><td>Program for the control the equipment</td><td>National Instruments Corporation</td><td>Labview2016</td><td></td></tr><tr><td>Program for the data analysis</td><td>The MathWorks, Inc.</td><td>Matlab2015b</td><td></td></tr></tbody></table>

novel techniques for observing structural dynamics of photoresponsive liquid crystals

我々 はこの記事で赤外線 (IR) を時間分解振動分光法、時間分解電子回折を用いた液晶 (LC) の段階で分子の測定実験を紹介します。液晶相転移、固体・液体の段階の間に存在する問題の重要な状態、有機エレクトロニクスのように自然のシステムと同様に共通。液晶配向を命じたが、緩く詰められて、したがって、内部構造と LCs の分子の配向は外部からの刺激によって変更できます。時間分解回折技術を明らかにしたピコ秒スケール単結晶の分子動力学と多結晶体、構造体のパッキングの直接観察、ソフト材料の超高速ダイナミクスがぼやけてによって妨げられています。回折パターン。ここでは、時間分解赤外振動分光と光のコア部分をベアリング カラムナー液晶材料の超高速スナップショットを取得する電子回折法を報告します。差動検出解析の組み合わせの時間分解赤外振動分光、電子線回折構造とソフトマテリアルの光誘起ダイナミクスを特徴付けるための強力なツールです。

明確に定義された円柱状の積層構造を形成するため、中央の八員環ベビーベッド リングの表示が予想されますので LC 分子の光コアユニットとして鞍型 π ベビーベッド スケルトン43,44しました、光誘起構造変化の励起状態の芳香族性19,45により平らな形に変更します。この材料の?...

Watch this Scientific Journal Video about Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals at JoVE.com

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals

ここでは、提案する、柱状の光励起分子中の局所構造の変形の観察を可能にする時間分解赤外振動分光法、電子回折の差分検出解析のプロトコル液晶、原子の視点を与える構造とこの光活性物質の動態との関係。

光応答性液晶の構造ダイナミクスを観察する手法

We discuss in this article the experimental measurements of the molecules in liquid crystal (LC) phase using the time-resolved infrared (IR) vibrational ...

novel-techniques-for-observing-structural-dynamics-photoresponsive

Research

JoVE Journal

Chemistry

8.7K ビュー.  Okayama University. ここでは、提案する、柱状の光励起分子中の局所構造の変形の観察を可能にする時間分解赤外振動分光法、電子回折の差分検出解析のプロトコル液晶、原子の視点を与える構造とこの光活性物質の動態との関係。

ビデオ: Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals

Patterning via Optical Saturable Transitions - Fabrication and Characterization

This protocol describes the fabrication and characterization of nanostructures using a novel nanolithographic technique called Patterning via Optical Saturable Transitions (POST). In this technique the chemical properties of organic photochromic molecules that undergo single-photon reactions are exploited, enabling rapid top-down nanopatterning over large areas at low light intensities, thereby, allowing for the circumvention of the far-field diffraction barrier.4 Simple, cost-effective, high throughput and resolution alternatives to nanopatterning are being explored, such as, two-photon polymerization5,6, beam pen lithography (BPL)7, scanning electron beam lithography (SEBL), and focused ion beam (FIB) patterning. However, multi-photon approaches require high light intensities, which limit their potential for high throughput and offer low image contrast. Although, electron and ion beam lithographic processes offer increased resolution, the serial nature of the process is limited to slow writing speeds, which also prevents patterning of features over large areas. Beam-pen lithography is an approach towards parallel near-field optical lithography. However, the gap between the source of the beam and the surface of the photoresist needs to be controlled extremely precisely for good pattern uniformity and this is very challenging to accomplish for large arrays of beams. Patterning via Optical Saturable Transitions (POST) is an alternative optical nanopatterning technique for patterning sub-wavelength features1-3. Since this technique uses single photons instead of electrons, it is extremely fast and does not require high light intensities1-3, opening the door to massive parallelization.

We report that the diffraction limit of conventional optical lithography can be overcome by exploiting the transitions of organic photochromic derivatives induced by their photoisomerization at low light intensities.1-3 This paper outlines our fabrication technique and two locking mechanisms, namely: dissolution of one photoisomer and electrochemical oxidation.

光可飽和遷移を経由してパターニング - 作製と特性評価

This protocol describes the fabrication and characterization of nanostructures using a novel nanolithographic technique called Patterning via Optical ...

工学

Free-form Light Actuators &#8212; Fabrication and Control of Actuation in Microscopic Scale

Liquid crystalline elastomers (LCEs) are smart materials capable of reversible shape-change in response to external stimuli, and have attracted researchers&#39; attention in many fields. Most of the studies focused on macroscopic LCE structures (films, fibers) and their miniaturization is still in its infancy. Recently developed lithography techniques, e.g., mask exposure and replica molding, only allow for creating 2D structures on LCE thin films. Direct laser writing (DLW) opens access to truly 3D fabrication in the microscopic scale. However, controlling the actuation topology and dynamics at the same length scale remains a challenge.
In this paper we report on a method to control the liquid crystal (LC) molecular alignment in the LCE microstructures of arbitrary three-dimensional shape. This was made possible by a combination of direct laser writing for both the LCE structures as well as for micrograting patterns inducing local LC alignment. Several types of grating patterns were used to introduce different LC alignments, which can be subsequently patterned into the LCE structures. This protocol allows one to obtain LCE microstructures with engineered alignments able to perform multiple opto-mechanical actuation, thus being capable of multiple functionalities. Applications can be foreseen in the fields of tunable photonics, micro-robotics, lab-on-chip technology and others.

Here, we fabricate 3D polymeric micro/nano structures in which both the shape and the molecular alignment can be engineered with nanometer scale accuracy by the use of direct laser writing. Light induced deformation of several types of liquid crystalline elastomer microstructures can be controlled in the microscopic scale.

自由形式のライトアクチュエータ - 顕微鏡スケールでの作製と作動の制御

Liquid crystalline elastomers (LCEs) are smart materials capable of reversible shape-change in response to external stimuli, and have attracted ...

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets

In liquid crystal (LC) physical chemistry, molecules near the surface play a great role in controlling bulk orientation. Thus far, mainly to achieve desired molecular orientation states in LC displays, the "static" surface property of LCs, so-called surface anchoring, has been intensively studied. As a rule of thumb, once the initial orientation of LCs is "locked" by specific surface treatments, such as rubbing or treatment with a specific alignment layer, it hardly changes with temperature. Here, we present a system exhibiting an orientational transition upon temperature variation, which conflicts with the consensus. Right on the transition, the bulk LC molecules experience the orientational rotation, with 90&#176; between the planar (P) orientation at high temperatures and the vertical (V) orientation at low temperatures in the first-order transitional manner. We have tracked thermodynamic surface anchoring behavior by means of polarizing optical microscopy (POM), dielectric spectroscopy (DS), high-resolution differential scanning calorimetry (HR-DSC), and grazing incidence X-ray diffraction (GI-XRD) and reached a plausible physical explanation: that the transition is triggered by a growth of surface wetting sheets, which impose the V orientation locally against the P orientation in the bulk. This landscape would provide a general link explaining how the equilibrium bulk orientation is affected by surface-localized orientation in many LC systems. In our characterization, POM and DS are advantageous by offering information on the spatial distribution of the orientation of LC molecules. HR-DSC gives information about the precise thermodynamic information on transitions, which cannot be addressed by conventional DSC instruments due to limited resolution. GI-XRD provides information on surface-specific molecular orientation and short-range orderings. The goal of this paper is to present a protocol for preparing a sample that exhibits the transition and to demonstrate how the thermodynamic structural variation, both in the bulk and on surfaces, can be analyzed through the abovementioned methods.

Here, we present a protocol to trigger an orientational transition of a liquid crystal in response to temperature. Methodologies are described for preparing a sample in order to observe the transition and the detailed transitional evolution.

界面湿潤シートの熱力学的成長によって引き起こされる液晶の配向転移

In liquid crystal (LC) physical chemistry, molecules near the surface play a great role in controlling bulk orientation. Thus far, mainly to achieve ...

Preparation of Liquid Crystal Networks for Macroscopic Oscillatory Motion Induced by Light

A strategy based on doped liquid crystalline networks is described to create mechanical self-sustained oscillations of plastic films under continuous light irradiation. The photo-excitation of dopants that can quickly dissipate light into heat, coupled with anisotropic thermal expansion and self-shadowing of the film, gives rise to the self-sustained deformation. The oscillations observed are influenced by the dimensions and the modulus of the film, and by the directionality and intensity of the light. The system developed offers applications in energy conversion and harvesting for soft-robotics and automated systems.
The general method described here consists of creating free-standing liquid crystalline films and characterizing the mechanical and thermal effects observed. The molecular alignment is achieved using alignment layers (rubbed polyimide), commonly used in the display manufacturing industry. To obtain actuators with large deformation, the mesogens are aligned and polymerized in a splay/bend configuration, i.e., with the director of the liquid crystals (LCs) going gradually from planar to homeotropic through the film thickness. Upon irradiation, the mechanical and thermal oscillations obtained are monitored with a high-speed camera. The results are further quantified by image analysis using an image processing program.

The goal of the protocol is to create liquid crystalline polymer films that can mechanically oscillate under continuous light irradiation. We describe in great detail the conception of free-standing films, from the liquid crystal alignment method to the photo-actuation. The experimental protocol applied to prepare this material is broadly applicable.

巨視的揺動運動の光によって誘起される液晶ネットワークの準備

A strategy based on doped liquid crystalline networks is described to create mechanical self-sustained oscillations of plastic films under continuous ...

Microfluidic Chips for In Situ Crystal X-ray Diffraction and In Situ Dynamic Light Scattering for Serial Crystallography

This protocol describes fabricating microfluidic devices with low X-ray background optimized for goniometer based fixed target serial crystallography. The devices are patterned from epoxy glue using soft lithography and are suitable for in situ X-ray diffraction experiments at room temperature. The sample wells are lidded on both sides with polymeric polyimide foil windows that allow diffraction data collection with low X-ray background. This fabrication method is undemanding and inexpensive. After the sourcing of a SU-8 master wafer, all fabrication can be completed outside of a cleanroom in a typical research lab environment. The chip design and fabrication protocol utilize capillary valving to microfluidically split an aqueous reaction into defined nanoliter sized droplets. This loading mechanism avoids the sample loss from channel dead-volume and can easily be performed manually without using pumps or other equipment for fluid actuation. We describe how isolated nanoliter sized drops of protein solution can be monitored in situ by dynamic light scattering to control protein crystal nucleation and growth. After suitable crystals are grown, complete X-ray diffraction datasets can be collected using goniometer based in situ fixed target serial X-ray crystallography at room temperature. The protocol provides custom scripts to process diffraction datasets using a suite of software tools to solve and refine the protein crystal structure. This approach avoids the artefacts possibly induced during cryo-preservation or manual crystal handling in conventional crystallography experiments. We present and compare three protein structures that were solved using small crystals with dimensions of approximately 10-20 &#181;m grown in chip. By crystallizing and diffracting in situ, handling and hence mechanical disturbances of fragile crystals is minimized. The protocol details how to fabricate a custom X-ray transparent microfluidic chip suitable for in situ serial crystallography. As almost every crystal can be used for diffraction data collection, these microfluidic chips are a very efficient crystal delivery method.

Microfluidic Chips for In Situ Crystal X-ray Diffraction and In Situ Dynamic Light Scattering for Serial Crystallography

This protocol describes in detail how to fabricate and operate microfluidic devices for X-ray diffraction data collection at room temperature. Additionally, it describes how to monitor protein crystallization by dynamic light scattering and how to process and analyze obtained diffraction data.

シリアル結晶の結晶 x 線回折その場その場での動的光散乱のためのマイクロ流体チップ

This protocol describes fabricating microfluidic devices with low X-ray background optimized for goniometer based fixed target serial crystallography. The ...

化学

Microfluidic Preparation of Liquid Crystalline Elastomer Actuators

This paper focuses on the microfluidic process (and its parameters) to prepare actuating particles from liquid crystalline elastomers. The preparation usually consists in the formation of droplets containing low molar mass liquid crystals at elevated temperatures. Subsequently, these particle precursors are oriented in the flow field of the capillary and solidified by a crosslinking polymerization, which produces the final actuating particles. The optimization of the process is necessary to obtain the actuating particles and the proper variation of the process parameters (temperature and flow rate) and allows variations of size and shape (from oblate to strongly prolate morphologies) as well as the magnitude of actuation. In addition, it is possible to vary the type of actuation from elongation to contraction depending on the director profile induced to the droplets during the flow in the capillary, which again depends on the microfluidic process and its parameters. Furthermore, particles of more complex shapes, like core-shell structures or Janus particles, can be prepared by adjusting the setup. By the variation of the chemical structure and the mode of crosslinking (solidification) of the liquid crystalline elastomer, it is also possible to prepare actuating particles triggered by heat or UV-vis irradiation.

This article describes the microfluidic process and parameters to prepare actuating particles from liquid crystalline elastomers. This process allows the preparation of actuating particles and the variation of their size and shape (from oblate to strongly prolate, core-shell, and Janus morphologies) as well as the magnitude of actuation.

液晶エラストマーのアクチュエータのマイクロの準備

This paper focuses on the microfluidic process (and its parameters) to prepare actuating particles from liquid crystalline elastomers. The preparation ...

Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals

Materials showing coupling phenomena between magnetism and (ferro)electricity, i.e., magnetoelectric effects, have attracted a great deal of attention due to their potential applications for future device technologies such as sensors and storage. However, conventional approaches, which usually utilize materials containing magnetic metal ions (or radicals), have a major problem: only a few materials have been found to show the coupling phenomena at room temperature. Recently, we proposed a new approach to achieve room-temperature magnetoelectrics. In contrast to conventional approaches, our alternative proposal focuses on a completely different material, a &#34;liquid crystal&#34;, free from magnetic metal ions. In such liquid crystals, a magnetic field can be utilized to control the orientational state of constituent molecules and the corresponding electric polarization through magnetic anisotropy of the molecules; it is an unprecedented mechanism of the magnetoelectric effect. In this context, this paper provides a protocol to measure ferroelectric properties induced by a magnetic field, that is, the direct magnetoelectric effect, in a liquid crystal. With the method detailed here, we successfully detected magnetically-tuned electric polarization in the chiral smectic C phase of a liquid crystal at room temperature. Taken together with the flexibility of constituent molecules, which directly affects the magnetoelectric responses, the introduced method will serve to allow liquid crystal cells to acquire more functions as room-temperature magnetoelectrics and associated optical materials.

In this report, we present a protocol to examine direct magnetoelectric effects, i.e., induction of ferroelectric polarization by applying magnetic fields, in liquid crystals. This protocol provides a unique approach, supported by the softness of liquid crystals, to achieve room-temperature magnetoelectrics.

液晶における強誘電分極の磁場調整を測定

Materials showing coupling phenomena between magnetism and (ferro)electricity, i.e., magnetoelectric effects, have attracted a great deal of attention due ...

An Electrochemical Cholesteric Liquid Crystalline Device for Quick and Low-Voltage Color Modulation

We demonstrate a method for fabricating a prototype reflective display device that contains cholesteric liquid crystal (LC) as an active component. The cholesteric LC is composed of a nematic LC 4&#39;-pentyloxy-4-cyanobiphenyl (5OCB), redox-responsive chiral dopant (FcD), and a supporting electrolyte 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMIm-OTf). The most important component is FcD. This molecule changes its helical twisting power (HTP) value in response to redox reactions. Therefore, in situ electrochemical redox reactions in the LC mixture allow for the device to change its reflection color in response to electrical stimuli. The LC mixture was introduced, by a capillary action, into a sandwich-type ITO glass cell comprising two glass slides with patterned indium tin oxide (ITO) electrodes, one of which was coated with poly(3,4-ethylenedioxythiophene)-co-poly(ethylene glycol) doped with perchlorate (PEDOT+). Upon application of +1.5 V, the reflection color of the device changed from blue (467 nm) to green (485 nm) in 0.4 s. Subsequent application of 0 V made the device recover the original blue color in 2.7 s. This device is characterized by its fastest electrical response and lowest operating voltage among any previously reported cholesteric LC device. This device could pave the way for the development of next generation reflective displays with low energy consumption rates.

A protocol for the fabrication of a reflective cholesteric liquid crystalline display device containing a redox-responsive chiral dopant allowing quick and low-voltage operation is presented.

迅速かつ低電圧の色変調のため電気化学コレステリック液晶結晶デバイス

We demonstrate a method for fabricating a prototype reflective display device that contains cholesteric liquid crystal (LC) as an active component. The ...

Preparation of Monodomain Liquid Crystal Elastomers and Liquid Crystal Elastomer Nanocomposites

LCEs are shape-responsive materials with fully reversible shape change and potential applications in medicine, tissue engineering, artificial muscles, and as soft robots. Here, we demonstrate the preparation of shape-responsive liquid crystal elastomers (LCEs) and LCE nanocomposites along with characterization of their shape-responsiveness, mechanical properties, and microstructure. Two types of LCEs &#8212; polysiloxane-based and epoxy-based &#8212; are synthesized, aligned, and characterized. Polysiloxane-based LCEs are prepared through two crosslinking steps, the second under an applied load, resulting in monodomain LCEs. Polysiloxane LCE nanocomposites are prepared through the addition of conductive carbon black nanoparticles, both throughout the bulk of the LCE and to the LCE surface. Epoxy-based LCEs are prepared through a reversible esterification reaction. Epoxy-based LCEs are aligned through the application of a uniaxial load at elevated (160 &#176;C) temperatures. Aligned LCEs and LCE nanocomposites are characterized with respect to reversible strain, mechanical stiffness, and liquid crystal ordering using a combination of imaging, two-dimensional X-ray diffraction measurements, differential scanning calorimetry, and dynamic mechanical analysis. LCEs and LCE nanocomposites can be stimulated with heat and/or electrical potential to controllably generate strains in cell culture media, and we demonstrate the application of LCEs as shape-responsive substrates for cell culture using a custom-made apparatus.

We demonstrate the preparation of siloxane-based and epoxy-based liquid crystal elastomers (LCEs) and LCE nanocomposites. The LCEs are characterized with respect to reversible strain, liquid crystal ordering, and stiffness. As a potential application, we demonstrate their use as shape-responsive substrates in a custom device for active cell culture.

モノドメイン液晶エラストマーおよび液晶エラストマーナノコンポジットの調製

LCEs are shape-responsive materials with fully reversible shape change and potential applications in medicine, tissue engineering, artificial muscles, and ...

生物工学

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal

Smart viscoelastic materials that respond to specific stimuli are one of the most attractive classes of materials important to future technologies, such as on-demand switchable adhesion technologies, actuators, molecular clutches, and nano-/microscopic mass transporters. Recently it was found that through a special solid-liquid transition, rheological properties can exhibit significant changes, thus providing suitable smart viscoelastic materials. However, designing materials with such a property is complex, and forward and backward switching times are usually long. Therefore, it is important to explore new working mechanisms to realize solid-liquid transitions, shorten the switching time, and enhance the contrast of rheological properties during switching. Here, a light-induced crystal-liquid phase transition is observed, which is characterized by means of polarizing light microscopy (POM), photorheometry, photo-differential scanning calorimetry (photo-DSC), and X-ray diffraction (XRD). The light-induced crystal-liquid phase transition presents key features such as (1) fast switching of crystal-liquid phases for both forward and backward reactions and (2) a high contrast ratio of viscoelasticity. In the characterization, POM is advantageous in offering information on the spatial distribution of LC molecule orientations, determining the type of liquid crystalline phases appearing in the material, and studying the orientation of LCs. Photorheometry allows measurement of a material&#8217;s rheological properties under light stimuli and can reveal the photorheological switching properties of materials. Photo-DSC is a technique to investigate thermodynamic information of materials in darkness and under light irradiation. Lastly, XRD allows studying of microscopic structures of materials. The goal of this article is to clearly present how to prepare and measure the discussed properties of a photorheological material.

This protocol demonstrates the preparation of a photorheological material that exhibits a solid phase, various liquid crystalline phases, and an isotropic liquid phase by increasing temperature. Presented here are methods for measuring the structure-viscoelasticity relationship of the material.

ツイストベンドネマティック液晶の高コントラストと高速フォトレオロジースイッチング

Smart viscoelastic materials that respond to specific stimuli are one of the most attractive classes of materials important to future technologies, such ...