Microhydraulic Electrowetting Actuators
Journal Article - Open Access
MIT Lincoln Laboratory Lexington United States
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The conversion of electrical to mechanical power on a subcentimeter scale is a key technology in many microsystems and energy harvesting devices. In this paper we present a type of capacitive energy conversion device that uses capillary pressure and electrowetting to reversibly convert electrical power to hydraulic power. These microhydraulic actuators use high surface to volume ratio to deliver high power at a relatively low voltage, with an energy conversion efficiency of over 65. The pressure generated by capillary effects grows linearly with shrinking capillary diameter, as does the frequency of actuation. We present the pressure, frequency, and power scaling properties of these actuators and demonstrate that power density scales up as the inverse capillary diameter squared, leading to high efficiency actuators with strength density exceeding biological muscle. Two potential applications for microhydraulics are also demonstrated soft-microrobotics and energy harvesting.
- Machinery and Tools
- Non-electrical Energy Conversion