Electroosmotic Soft Actuators

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dc.contributor.advisorSmela, Elisabethen_US
dc.contributor.authorSritharan, Deepaen_US
dc.contributor.departmentMechanical Engineeringen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.date.accessioned2018-01-23T06:35:48Z
dc.date.available2018-01-23T06:35:48Z
dc.date.issued2017en_US
dc.description.abstractThis dissertation details the research involved in creating the first paper-based soft actuator driven by electroosmosis. To accomplish this, research breakthroughs were made in the fields of electrokinetic pumping and device manufacturing using soft materials. Electroosmosis is an electrically induced microfluidic flow phenomenon. When an electric field is applied to the fluid, across the microchannels, electroosmotic flow occurs in the direction of the applied electric field. In this work, liquid was electroosmotically displaced within a flexible microfluidic device to actuate an elastomeric membrane. The goal of this work was to create a fully sealed fluidic actuator. It was therefore necessary to encapsulate the pumping fluid within the device, and to maximize pressure it was necessary to eliminate compliance caused by trapped gases. Electrolytic gas formation is well known to disrupt pumping in DC electroosmotic systems that use water as the pumping liquid. In this work, electrolysis was eliminated by replacing water with propylene carbonate (PC): PC was determined to be electrochemically stable up to at least 10 kV, in the absence of moisture or salt contaminants. Bubble-free electroosmotic pumping with PC was achieved within sealed miniature actuators, which could be continuously operated for at least one hour. Benchtop fabrication techniques were developed to build encapsulated fluidic actuators composed entirely of soft, flexible materials. Stretchable electrochemically stable electrodes were made using a conductive paint made by mixing carbon nanoparticles into a silicone base. High-density microchannel networks were incorporated by using paper and other flexible porous materials, instead of conventional planar replica-molded microchannels. The device was filled with pumping fluid without the use of external tubing, and then encapsulated by casting a film of elastomer over the filled reservoir to form the actuating membrane. The resulting actuators were flexible and stretchable, demonstrating significant membrane deformations (hundreds of micrometers) within seconds of applying the electric field and ability to lift large loads (tens of grams). These polymeric electroosmotic actuators are unique among electroactive polymer actuators because they are able to simultaneously generate high force as well as large stroke. It is envisioned that this research will pave the way for the creation of artificial muscles and smart shape-changing materials that can be actuated by electroosmosis.en_US
dc.identifierhttps://doi.org/10.13016/M24M91C39
dc.identifier.urihttp://hdl.handle.net/1903/20309
dc.language.isoenen_US
dc.subject.pqcontrolledRoboticsen_US
dc.subject.pqcontrolledChemistryen_US
dc.subject.pqcontrolledDesignen_US
dc.subject.pquncontrolledelastomeren_US
dc.subject.pquncontrolledelectrokineticsen_US
dc.subject.pquncontrolledelectrolysis-freeen_US
dc.subject.pquncontrolledflexibleen_US
dc.subject.pquncontrolledfluidicsen_US
dc.subject.pquncontrolledpaper microfluidicsen_US
dc.titleElectroosmotic Soft Actuatorsen_US
dc.typeDissertationen_US

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