Os autores gostariam de agradecer Ryan Tung por sua ajuda e discussões técnicas úteis. Os autores também gostariam de agradecer o apoio e suporte da equipe técnica Birck Nanotechnology Center. Este trabalho foi financiado pela Agência de Projetos de Pesquisa Avançada de Defesa sob a Purdue Microondas Reconfigurable Evanescentes-Mode Cavity Filtros de Estudo. E também pela NNSA Centro de Previsão de Confiabilidade, Integridade e sobrevivência de Microsystems e do Departamento de Energia sob Prêmio Número DE-FC5208NA28617. Os pontos de vista, opiniões e / ou conclusões contidas neste documento / apresentação são de responsabilidade dos autores / apresentadores e não deve ser interpretada como representando as opiniões ou políticas oficiais, expressa ou implícita, da Agência de Projetos de Pesquisa Avançada de Defesa ou o Departamento da Defesa.

<ol>
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A., Bruyker, D. D., Volkel, A. R., Peeters, E., Dunec, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+external+electrode+configuration+for+the+electrostatic+actuation+of+MEMS+based+devices.">A novel external electrode configuration for the electrostatic actuation of MEMS based devices.</a> J. Micromech. Microeng. 14, 446-451 (2004).</li><li>Rottenberg, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrostatic+fringing-field+actuator+(EFFA):+application+towards+a+low-complexity+thin+film+RF-MEMS+technology.">Electrostatic fringing-field actuator (EFFA): application towards a low-complexity thin film RF-MEMS technology.</a> J. Micromech. Microeng. 17, S204-S210 (2007).</li><li>Allen, W. N., Small, J., Liu, X., Peroulis, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bandwidth-optimal+single+shunt-capacitor+matching+networks+for+parallel+RC+loads+of+Q+&gt;&gt;+1.">Bandwidth-optimal single shunt-capacitor matching networks for parallel RC loads of Q &gt;&gt; 1.</a> Asia-Pacific Microw. Conf (Singapore). , 2128-2131 (2009).</li><li>Small, J., Liu, X., Garg, A., Peroulis, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrostatically+tunable+analog+single+crystal+silicon+fringing-field+MEMS+varactor.">Electrostatically tunable analog single crystal silicon fringing-field MEMS varactor.</a> Asia-Pacific Microw Conf (Singapore). , 575-578 (2009).</li><li>Liu, X., Small, J., Berdy, D., Katehi, L. P. B., Chappell, W. J., Peroulis, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+mechanical+vibration+on+the+performance+of+RF+MEMS+evanescent-mode+tunable+resonators.">Impact of mechanical vibration on the performance of RF MEMS evanescent-mode tunable resonators.</a> IEEE Microw. Wireless Compon. Lett. 21, 406-408 (2011).</li><li>Small, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrostatic+fringing+field+actuation+for+pull-in+free+RF-MEMS+analog+tunable+resonators.">Electrostatic fringing field actuation for pull-in free RF-MEMS analog tunable resonators.</a> J. Micromech. Microeng. 22, 095004 (2012).</li><li>Su, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> A lateral-drive method to address pull-in failure in MEMS. , (2008).</li><li>Scott, S., Peroulis, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+capacitively-loaded+MEMS+slot+element+for+wireless+temperature+sensing+of+up+to+300&#176;C+.">A capacitively-loaded MEMS slot element for wireless temperature sensing of up to 300&#176;C .</a> , 1161-1164 (2009).</li><li>Scott, S., Sadeghi, F., Peroulis, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inherently-robust+300C+MEMS+sensor+for+wireless+health+monitoring+of+ball+and+rolling+element+bearings.">Inherently-robust 300C MEMS sensor for wireless health monitoring of ball and rolling element bearings.</a> , 975-978 (2009).</li><li>Lee, K. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-contact+electrostatic+microactuator+using+slit+structures:+theory+and+a+preliminary+test.">Non-contact electrostatic microactuator using slit structures: theory and a preliminary test.</a> J. Micromech. Microeng. 17, 2186-2196 (2007).</li><li>Su, J., Yang, H., Fay, P., Porod, W., Berstein, G. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+surface+micromachined+offset-drive+method+to+extend+the+electrostatic+travel+range.">A surface micromachined offset-drive method to extend the electrostatic travel range.</a> J. Micromech. Microeng. 20, 015004 (2010).</li><li>Small, J., Fruehling, A., Garg, A., Liu, X., Peroulis, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DC-dynamic+biasing+for+&gt;50x+switching+time+improvement+in+severely+underdamped+fringing-field+electrostatic+MEMS+actuators.">DC-dynamic biasing for &gt;50x switching time improvement in severely underdamped fringing-field electrostatic MEMS actuators.</a> J. Micromech. Microeng. 22, (2012).</li><li>Borovic, B., Liu, A. Q., Popa, D., Cai, H., Lewis, F. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Open-loop+versus+closed-loop+control+of+MEMS+devices:+Choices+and+issues.">Open-loop versus closed-loop control of MEMS devices: Choices and issues.</a> J. Micromech. Microeng. 15, 1917-1924 (2005).</li><li>Pons-Nin, J., Rodriquez, A., Castaner, L. 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F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Residual+vibration+suppression+for+duffing+nonlinear+systems+with+electromagnetical+actuation+using+nonlinear+command+shaping+techniques.">Residual vibration suppression for duffing nonlinear systems with electromagnetical actuation using nonlinear command shaping techniques.</a> ASME J. Vibration and Acoustics. 128, 778-789 (2006).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Transene Sulfite Gold TSG-250. Product Number: 110-TSG-250. , (2012).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Gold etchant type TFA. 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Baixa tensão residual Au deposição de película e uma libertação seca com Xef dois componentes são criticamente bem sucedido na fabricação do dispositivo. Eletrostáticos atuadores franjas em campo fornecimento de forças relativamente baixos quando comparados com os atuadores de campo de placas paralelas. MEMS típicas tensões fina película de&gt; 60 MPa resultará em tensões de acionamento excessivo, que pode comprometer a confiabilidade dos EFFA MEMS. Por esta razão, a receita galvanoplastia é...

Sistemas Microeletromecânicos (MEMS) utilizam vários mecanismos de accionamento para atingir o deslocamento mecânico. Os mais populares são térmica, piezoelétrico, magnetostático e eletrostática. Por tempo de comutação curto, atuação eletrostática é a técnica mais popular, 1, 2. Na prática, projetos mecânicos criticamente amortecida oferecer o melhor compromisso entre o tempo de subida inicial e tempo de repouso. Após a aplicação do viés DC e acionamento da membrana em direção ao eletrodo de pull-down, o tempo de estabilização não é uma questão importante como a membrana se encaixará para baixo e aderir ao eletrodo revestido atuação dielétrico. Vários pedidos foram beneficiados pelo projeto atuação eletrostática acima mencionado 3-8. No entanto, a presença do eléctrodo de suspenso dieléctrica revestida faz com que o actuador susceptível de carregamento dieléctrico e agarramento. Membranas MEMS podem utilizar um udesenho mecânico nderdamped para conseguir um tempo inicial rápida ascensão. Um exemplo de um projeto mecânico subamortecido é a franja-campo eletrostático acionada (EFFA) MEMS. Esta topologia tem exibido muito menos vulnerabilidade a mecanismos típicos de falhas que afligem projetos baseados eletrostáticas 9-20. A ausência de contra-eletrodo paralelo e, conseqüentemente, o campo elétrico paralelo é por isso que estes MEMS são apropriadamente chamadas &quot;franjas-campo&quot; acionada (Figura 1). Para o projeto EFFA, o eletrodo de pull-down é dividido em dois eletrodos separados que são posicionados lateralmente deslocado para a membrana em movimento, eliminando completamente a sobreposição entre as partes móveis e fixas do dispositivo. No entanto, a remoção do substrato por debaixo da membrana móvel reduz significativamente o filme de compressão de amortecimento do componente, aumentando assim o tempo de estabilização. Figura 2B é um exemplo da resolução de tempo em resposta a Standard passo de polarização. Transientes, ou DC-dinâmica aplicada polarização em tempo real pode ser utilizado para melhorar o tempo de assentamento 20-26. Figuras 2C e 2D ilustram qualitativamente como uma forma de onda variável no tempo pode cancelar eficazmente o toque. Esforços de pesquisa anteriores utilizar métodos numéricos para calcular a tensão precisa e horários da polarização de entrada para melhorar o tempo de comutação. O método neste trabalho utiliza compactos expressões de forma fechada para calcular os parâmetros de forma de onda de polarização de entrada. Além disso, o trabalho anterior focou paralelo placa de accionamento. Embora as estruturas são projetadas para serem subamortecido, amortecimento squeeze-filme ainda está disponível nesta configuração. O método de atuação apresentada neste trabalho é franjas-campo de atuação. Nesta configuração amortecimento squeeze-film é efetivamente eliminado. Isto representa um caso extremo em que o amortecimento mecânico do feixe de MEMS é muito baixo. Este artigo descreve como fabricar o dev EFFA MEMSices e realizar a medição para validar experimentalmente o conceito de forma de onda.

<table border="0" cellpadding="0" cellspacing="0" width="746">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:251px;">Chemical</td>
			<td style="width:163px;">Company</td>
			<td style="width:137px;">Catalogue number</td>
			<td style="width:195px;">Comments (optional)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Buffered oxide etchant</td>
			<td>Mallinckrodt Baker</td>
			<td>1178</td>
			<td>Silicon dioxide etch, Ti etch</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Acetone</td>
			<td>Mallinckrodt Baker</td>
			<td>5356</td>
			<td>wafer clean</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Isopropyl alcohol</td>
			<td>Honeywell</td>
			<td>BDH-140</td>
			<td>wafer clean</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Hexamethyldisilizane</td>
			<td>Mallinckrodt Baker</td>
			<td>5797</td>
			<td>adhesion promoter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Microposit SC 1827 Positive Photoresist</td>
			<td>Shipley Europe Ltd</td>
			<td>44090</td>
			<td>Pattern, electroplating</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Microposit MF-26A developer</td>
			<td>Shipley Europe Ltd</td>
			<td>31200</td>
			<td>Develop SC 1827</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Tetramethylammonium hydroxide</td>
			<td>Sigma-Aldrich</td>
			<td>334901</td>
			<td>Bulk Si etch</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Hydrofluroic acid</td>
			<td>Sciencelab.com</td>
			<td>SLH2227</td>
			<td>Silicon dioxide etch</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Sulfuric acid</td>
			<td>Sciencelab.com</td>
			<td>SLS2539</td>
			<td>wafer clean</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Hydrogen peroxide</td>
			<td>Sciencelab.com</td>
			<td>SLH1552</td>
			<td>Wafer clean</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Transene Sulfite Gold TSG-250</td>
			<td>Transense</td>
			<td>110-TSG-250</td>
			<td>Au electroplating solution</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Baker PRS-3000 Positive Resist Stripper</td>
			<td>Mallinckrodt Baker</td>
			<td>6403</td>
			<td>Photoresist stripper</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Gold etchant type TFA</td>
			<td>Transense</td>
			<td>060-0015000</td>
			<td>Au etch</td>
		</tr>
	</tbody>
</table>

real-time dc-dynamic biasing method for switching time improvement in severely underdamped fringing-field electrostatic mems actuators

Mecanicamente subamortecido MEMS franjas de campo eletrostático atuadores são bem conhecidos por sua operação de comutação rápida em resposta a uma tensão de polarização de entrada degrau unitário. No entanto, em contrapartida, o desempenho melhorado de comutação é um tempo relativamente longo para chegar a resolver cada altura do espaço vazio em resposta a várias tensões aplicadas. Transient aplicadas formas de onda de preconceito são empregadas para facilitar tempos de comutação reduzidas para eletrostáticas MEMS franjas em campo atuadores com fatores de alta qualidade mecânica. Remover o substrato subjacente do atuador franjas-campo cria o ambiente de baixo amortecimento mecânico necessário testar efetivamente o conceito. A remoção do substrato subjacente tem também uma melhoria significativa sobre o desempenho do dispositivo de fiabilidade em relação a falhas devido ao atrito estático. Apesar de polarização DC-dinâmico é útil para melhorar o tempo de assentamento, as taxas de variação necessários para dispositivos MEMS típicos pode colocar exigências agressivas sobre a carga pumps para totalmente integrada projetos on-chip. Além disso, pode haver desafios que integram a etapa de remoção de substrato para as etapas de processamento CMOS comerciais back-end-of-line. Validação experimental de atuadores fabricados demonstra uma melhora de 50x em tempo de comutação em relação à etapa de polarização resultados convencionais. Em comparação com os cálculos teóricos, os resultados experimentais estão de acordo.

A configuração na Figura 4 é usado para capturar a deflexão contra características de tempo das pontes MEMS. Ao utilizar o Doppler vibrómetro a laser no modo de medição contínua, os parâmetros precisos de voltagem e de tempo podem ser encontrados para resultar em oscilação mínima do feixe para a altura do espaço vazio desejado. Figura 5 ilustra um exemplo de deflexão de feixe correspondente à altura do espaço vazio 60 V. Vê-se que praticamente toda a oscilação é rem...

Watch this Scientific Journal Video about Real-Time DC-dynamic Biasing Method for Switching Time Improvement in Severely Underdamped Fringing-field Electrostatic MEMS Actuators at JoVE.com

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

O design robusto dispositivo de franja-campo eletrostático atuadores MEMS resultados em condições de amortecimento de compressão de filme inerentemente baixos e longos tempos de sedimentação ao realizar operações de comutação usando polarização passo convencional. Em tempo real a mudança melhora o tempo com formas de ondas DC-dinâmicos reduz o tempo de estabilização de franjas em campo MEMS atuadores quando a transição entre-se para baixo e para baixo-à-up estados.

Real-Time DC-dinâmico método de polarização para a mudança de melhoria no tempo em Severamente subamortecido Fringing-campo eletrostático MEMS Atuadores

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

real-time-dc-dynamic-biasing-method-for-switching-time-improvement

Research

JoVE Journal

Engineering

10.2K visualizações.  University of California, Davis.  O design robusto dispositivo de franja-campo eletrostático atuadores MEMS resultados em condições de amortecimento de compressão de filme inerentemente baixos e longos tempos de sedimentação ao realizar operações de comutação usando polarização passo convencional. Em tempo real a mudança melhora o tempo com formas de ondas DC-dinâmicos reduz o tempo de estabilização de franjas em campo MEMS atuadores quando a transição entre-se para baixo e para baixo-?...

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

Fabrication Process of Silicone-based Dielectric Elastomer Actuators

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an elastomeric dielectric membrane sandwiched between two compliant electrodes. The large actuation strains of these transducers when used as actuators (over 300% area strain) and their soft and compliant nature has been exploited for a wide range of applications, including electrically tunable optics, haptic feedback devices, wave-energy harvesting, deformable cell-culture devices, compliant grippers, and propulsion of a bio-inspired fish-like airship. In most cases, DETs are made with a commercial proprietary acrylic elastomer and with hand-applied electrodes of carbon powder or carbon grease. This combination leads to non-reproducible and slow actuators exhibiting viscoelastic creep and a short lifetime. We present here a complete process flow for the reproducible fabrication of DETs based on thin elastomeric silicone films, including casting of thin silicone membranes, membrane release and prestretching, patterning of robust compliant electrodes, assembly and testing. The membranes are cast on flexible polyethylene terephthalate (PET) substrates coated with a water-soluble sacrificial layer for ease of release. The electrodes consist of carbon black particles dispersed into a silicone matrix and patterned using a stamping technique, which leads to precisely-defined compliant electrodes that present a high adhesion to the dielectric membrane on which they are applied.

This manuscript shows the fabrication process for the manufacture of dielectric elastomer soft actuators based on silicone membranes. The three key stages of production are presented in detail: blade casting of thin silicone membranes; pad printing of compliant electrodes; and the assembly of all the components.

Processo de fabricação de base de silicone dielétricos Elastomer Atuadores

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an ...

Engenharia

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.

Compact Lens-less Digital Holographic Microscope de Inspeção MEMS e Caracterização

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

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.

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

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.

Atuadores de luz de forma livre - Fabricação e Controle de atuação em escala microscópica

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

Fabrication of 3D Carbon Microelectromechanical Systems (C-MEMS)

A wide range of carbon sources are available in nature, with a variety of micro-/nanostructure configurations. Here, a novel technique to fabricate long and hollow glassy carbon microfibers derived from human hairs is introduced. The long and hollow carbon structures were made by the pyrolysis of human hair at 900 &#176;C in a N2 atmosphere. The morphology and chemical composition of natural and pyrolyzed human hairs were investigated using scanning electron microscopy (SEM) and electron-dispersive X-ray spectroscopy (EDX), respectively, to estimate the physical and chemical changes due to pyrolysis. Raman spectroscopy was used to confirm the glassy nature of the carbon microstructures. Pyrolyzed hair carbon was introduced to modify screen-printed carbon electrodes ; the modified electrodes were then applied to the electrochemical sensing of dopamine and ascorbic acid. Sensing performance of the modified sensors was improved as compared to the unmodified sensors. To obtain the desired carbon structure design, carbon micro-/nanoelectromechanical system (C-MEMS/C-NEMS) technology was developed. The most common C-MEMS/C-NEMS fabrication process consists of two steps: (i) the patterning of a carbon-rich base material, such as a photosensitive polymer, using photolithography; and (ii) carbonization through the pyrolysis of the patterned polymer in an oxygen-free environment. The C-MEMS/NEMS process has been widely used to develop microelectronic devices for various applications, including in micro-batteries, supercapacitors, glucose sensors, gas sensors, fuel cells, and triboelectric nanogenerators. Here, recent developments of a high-aspect ratio solid and hollow carbon microstructures with SU8 photoresists are discussed. The structural shrinkage during pyrolysis was investigated using confocal microscopy and SEM. Raman spectroscopy was used to confirm the crystallinity of the structure, and the atomic percentage of the elements present in the material before and after pyrolysis was measured using EDX.

Fabrication of 3D Carbon Microelectromechanical Systems C-MEMS

Long and hollow glassy carbon microfibers were fabricated based on the pyrolysis of a natural product, human hair. The two fabrication steps of carbon microelectromechanical and carbon nanoelectromechanical systems, or C-MEMS and C-NEMS, are: (i) photolithography of a carbon-rich polymer precursor and (ii) pyrolysis of the patterned polymer precursor.

Fabricação de sistemas 3D Microelectromecânicos de Carbono (C-MEMS)

A wide range of carbon sources are available in nature, with a variety of micro-/nanostructure configurations. Here, a novel technique to fabricate long ...

Design and Characterization Methodology for Efficient Wide Range Tunable MEMS Filters

Here, we demonstrate the advantages of the laser Doppler vibrometer (LDV) over conventional techniques (the network analyzer), as well as the techniques to create an application-based microelectromechanical systems (MEMS) filter and how to use it efficiently (i.e., tuning the tuning-capability and avoiding both failure and stiction). LDV enables crucial measurements that are impossible with the network analyzer, such as higher mode detection (highly sensitive biosensor application) and resonance measurement for very small devices (fast prototyping). Accordingly, LDV was used to characterize the frequency tuning range and resonance frequency at different modes of the MEMS filters built for this study. This wide range frequency tuning mechanism is based simply on Joule heating from the embedded heaters and relatively high thermal stress with respect to the temperature of a fixed-fixed beam. However, we demonstrate that another limitation of this method is the resulting high thermal stress, which can burn the devices. Further improvement was achieved and shown for the first time in this study, such that the tuning capability was increased by 32% through an increase in the applied DC bias voltage (25 V to 35 V) between the two adjacent beams. This important finding eliminates the need for the extra Joule heating at the wider frequency tuning range. Another possible failure is through stiction and requirement of structure optimization: We propose a simple and easy technique of low frequency square wave signal application that can successfully separate the beams and eliminates the need for the more sophisticated and complicated methods given in the literature. The above findings necessitate a design methodology, and so we also provide an application-based design.

A protocol for a fixed-fixed beam design using a laser Doppler vibrometer (LDV), including the measurement of frequency tuning, modification of tuning capability, and avoidance of device failure and stiction, is presented. The superiority of the LDV method over the network analyzer is demonstrated due to its higher mode capability.

Projeto e metodologia de caracterização para filtros de MEMS sintonizável eficiente gama

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

Growth and Electrostatic/chemical Properties of Metal/LaAlO3/SrTiO3 Heterostructures

The quasi 2D electron system (q2DES) that forms at the interface between LaAlO3 (LAO) and SrTiO3 (STO) has attracted much attention from the oxide electronics community. One of its hallmark features is the existence of a critical LAO thickness of 4 unit-cells (uc) for interfacial conductivity to emerge. Although electrostatic mechanisms have been proposed in the past to describe the existence of this critical thickness, the importance of chemical defects has been recently accentuated. Here, we describe the growth of metal/LAO/STO heterostructures in an ultra-high vacuum (UHV) cluster system combining pulsed laser deposition (to grow the LAO), magnetron sputtering (to grow the metal) and X-ray photoelectron spectroscopy (XPS). We study step by step the formation and evolution of the q2DES and the chemical interactions that occur between the metal and the LAO/STO. Additionally, magnetotransport experiments elucidate on the transport and electronic properties of the q2DES. This systematic work not only demonstrates a way to study the electrostatic and chemical interplay between the q2DES and its environment, but also unlocks the possibility to couple multifunctional capping layers with the rich physics observed in two-dimensional electron systems, allowing the fabrication of new types of devices.

Growth and Electrostatic/chemical Properties of Metal/LaAlO3/SrTiO3 Heterostructures

We fabricate metal/LaAlO3/SrTiO3 heterostructures using a combination of pulsed laser deposition and in situ magnetron sputtering. Through magnetotransport and in situ X-ray photoelectron spectroscopy experiments, we investigate the interplay between electrostatic and chemical phenomena of the quasi two-dimensional electron gas formed in this system.

Crescimento e eletrostático química/Propriedades de Metal/LaAlO3/SrTiO3 estende

The quasi 2D electron system (q2DES) that forms at the interface between LaAlO3 (LAO) and SrTiO3 (STO) has attracted much attention from the oxide ...

Fabrication of Soft Pneumatic Network Actuators with Oblique Chambers

Soft pneumatic network actuators have become one of the most promising actuation devices in soft robotics which benefits from their large bending deformation and low input. However, their monotonous bending motion form in two-dimensional (2-D) space keeps them away from wide applications. This paper presents a detailed fabrication method of soft pneumatic network actuators with oblique chambers, to explore their motions in three-dimensional (3-D) space. The design of oblique chambers enables actuators with tunable coupled bending and twisting capabilities, which gives them the possibility to move dexterously in flexible manipulators, to become biologically inspired robots and medical devices. The fabrication process is based on the molding method, including the silicone elastomer preparation, chamber and base parts fabrication, actuator assembly, tubing connections, checks for leaks, and actuator repair. The fabrication method guarantees the rapid manufacturing of a series of actuators with only a few modifications in the molds. The test results show the high quality of the actuators and their prominent bending and twisting capabilities. Experiments of the gripper demonstrate the advantages of the development in adapting to objects with different diameters and providing sufficient friction.

Here we present a fabrication method of soft pneumatic network actuators with oblique chambers. The actuators are capable of generating coupled bending and twisting motions, which broadens their application in soft robotics.

Fabricação de atuadores de rede pneumática macio com câmaras oblíquas

Soft pneumatic network actuators have become one of the most promising actuation devices in soft robotics which benefits from their large bending ...

Optimized Sealing Process and Real-Time Monitoring of Glass-to-Metal Seal Structures

Residual stress is an essential factor to keeping the hermeticity and robustness of a glass-to-metal seal structure. The purpose of this report is to demonstrate a novel protocol to characterize and measure residual stress in a glass-to-metal seal structure without destroying the insulation and hermeticity of sealing materials. In this research, a femto-laser inscribed fiber Bragg grating sensor is used. The glass-to-metal seal structure that is measured consists of a metal shell, sealing glass, and Kovar conductor. To make the measurements worthwhile, the specific heat treatment of metal-to-glass seal (MTGS) structure is explored to obtain the model with best hermeticity. Then, the FBG sensor is embedded into the path of sealing glass and becomes well-fused with the glass as the temperature cools to RT. The Bragg wavelength of FBG shifts with the residual stress generated in sealing the glass. To calculate the residual stress, the relationship between Bragg wavelength shift and strain is applied, and the finite element method is also used to make the results reliable. The online monitoring experiments of residual stress in sealing glass are carried out at different loads, such as high temperature and high pressure, to broaden functions of this protocol in harsh environments.

Key procedures to optimize the sealing process and achieve real-time monitoring of the metal-to-glass seal (MTGS) structure are described in detail. The embedded fiber Bragg grating (FBG) sensor is designed to achieve online monitoring of temperature and high-level residual stress in the MTGS with simultaneous environmental pressure monitoring.

Processo de vedação otimizado e monitoramento em tempo real de estruturas de vedação de vidro a metal

Residual stress is an essential factor to keeping the hermeticity and robustness of a glass-to-metal seal structure. The purpose of this report is to ...

Rapid Manufacturing of Thin Soft Pneumatic Actuators and Robots

This protocol describes a method for rapid manufacturing of soft pneumatic actuators and robots with an ultrathin form factor using a heat press and a laser cutter machine. The method starts with the lamination of thermoplastic polyurethane (TPU) sheets using a heat press for 10 min at the temperature of ~93 &#176;C. Next, the parameters of the laser cutter machine are optimized to produce a rectangular balloon with maximum burst pressure. Using the optimized parameters, the soft actuators are laser cut/welded three times sequentially. Next, a dispensing needle is attached to the actuator, allowing it to be inflated. The effect of geometrical parameters on the deflection of the actuator are studied systematically by varying the channel width and length. Finally, the performance of the actuator is characterized using an optical camera and a fluid dispenser. Conventional fabrication methods of soft pneumatic actuators based on silicone molding are time consuming (several hours). They also result in strong but bulky actuators, which limits the actuator&#8217;s applications. Moreover, microfabrication of thin pneumatic actuators is both time-consuming and expensive. The proposed manufacturing method in the current work resolves these issues by introducing a fast, simple, and cost-effective fabrication method of ultrathin pneumatic actuators.

This protocol describes a method for rapid manufacturing of soft pneumatic actuators and robots with a thin form factor. The fabrication method starts with lamination of thermoplastic polyurethane (TPU) sheets followed by laser cutting/welding of a two-dimensional pattern to form actuators and robots.

Fabricação rápida de atuadores e robôs pneumáticos macios finos

This protocol describes a method for rapid manufacturing of soft pneumatic actuators and robots with an ultrathin form factor using a heat press and a ...

Fabrication of Carbon-Based Ionic Electromechanically Active Soft Actuators

Ionic electromechanically active capacitive laminates are a type of smart material that move in response to electrical stimulation. Due to the soft, compliant and biomimetic nature of this deformation, actuators made of the laminate have received increasing interest in soft robotics and (bio)medical applications. However, methods to easily fabricate the active material in large (even industrial) quantities and with a high batch-to-batch and within-batch repeatability are needed to transfer the knowledge from laboratory to industry. This protocol describes a simple, industrially scalable and reproducible method for the fabrication of ionic carbon-based electromechanically active capacitive laminates and the preparation of actuators made thereof. The inclusion of a passive and chemically inert (insoluble) middle layer (e.g., a textile-reinforced polymer network or microporous Teflon) distinguishes the method from others. The protocol is divided into five steps: membrane preparation, electrode preparation, current collector attachment, cutting and shaping, and actuation. Following the protocol results in an active material that can, for example, compliantly grasp and hold a randomly shaped object as demonstrated in the article.

This article describes a fast and simple manufacturing process of ionic electromechanically active composite materials for actuators in biomedical, biomimetic and soft robotics applications. The key fabrication steps, their importance for the actuators&#39; final properties, and some of the main characterization techniques are described in detail.

Fabricação de atuadores macios eletromecanicamente ativos à base de carbono

Ionic electromechanically active capacitive laminates are a type of smart material that move in response to electrical stimulation. Due to the soft, ...