a.synthetic.leaf.for.energy.scavenging

Inspired by the transport of water in plants, we resently presented a synthetic, microfabricated 'leaf' which can scavenge electrical power from evaporation-driven flow via a charge pump embedded in the 'stem'. In the device, evaporation at the surface of the device produces flow in microfabricated vasculature. Gas-liquid interfaces within the vasculature move across conductive plates, generating changes in the capacitance of these plates. These capacitance changes are used to drive a rectified charge-pump circuit which uses each transition to increase the energy in a storage capacitor.

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transpiration.actuation.

Earlier, we developed devices inspired by a fern spore-release structure that generates forces due to the same Laplace-Young pressure mechanism that leads to conventional MEMS wet-release stiction. These actuators are ideal for applications where power or energy scavenging from the environment is desirable. Moreover, these devices enable actuation powered humidity in air. The methodology in this work leverages advances made in the fabrication of microchannels and MEMS actuators, and applies them to biomimicry to develop a new class of microfluidic actuators. Deflection profiles are programmed by device geometry. The work combines mechanical and fluidic domains in an integratable process that provides low-power actuation from microchannels. We demonstrated millimeters of deflection by liquid evaporation only

    R.T. Borno, J.D. Steinmeyer, and M. M. Maharbiz, "Transpiration actuation: the design, fabrication, and characterization of biomimetic microactuators driven by the surface tension of water," Journal of Micromechanics and Microengineering, 16, pg. 2375-2383, 2006.
figure sporangium

press.

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