Capillary Force Actuation for Achieving Large Deflections of an Elastomeric Membrane at Low Voltage

Abstract

Elastomeric materials offer many benefits to MEMS (Micro Electro Mechanical Systems).These benefits include smaller device footprints, greater range of motion, and lower required actuation forces. However, a complementary actuation technology is needed, to implement the capabilities of elastomeric components. Capillary forces are a novel and promising mechanism to produce motion in the flexible components of micro devices -such as elastomeric

Actuation of Flexible Membranes via Capillary Force: Single-Active-Surface Experiments

“…We highlight the results of five tests here; for further results see [ 13 ]. For all the prototypes discussed, bridge heights were set via the microbeads to be close to 100 μm.…”

“…A 30.6 nm aluminum oxide (Al 2 O 3 ) film was grown by anodization (18 V) [ 12 ]. An ultrathin (50.8 nm) film of the hydrophobic fluoropolymer CYTOP-809 (Bellex International Corporation, Wilmington, DE, USA) was deposited on the oxide film via spin coating and the slides were then baked at 160° for 1 h [ 13 ]. To complete the fabrication of the active surface, a silicon oil mixture (Dow Corning OS-10, OS-20, and OS-30, Krayden, Inc., Denver, CO, USA, 1:8:1 by weight), was applied to the CYTOP and then allowed to evaporate from the surface.…”

“…To complete the fabrication of the active surface, a silicon oil mixture (Dow Corning OS-10, OS-20, and OS-30, Krayden, Inc., Denver, CO, USA, 1:8:1 by weight), was applied to the CYTOP and then allowed to evaporate from the surface. This treatment was found to reduce contact angle hysteresis and yield more repeatable electrowetting [ 13 , 14 ]. (Contact angle hysteresis was typically 10° after treatment).…”

“…While dimensions vary among the devices tested, the working components occupy a region of dimensions approximately 2 mm × 2 mm × 0.5 mm. Devices with smaller dimensions should be equally effective according to theory [ 13 ] but were not examined in this initial investigation due to the design constraints imposed by simple fabrication procedures and liquid bridge observation.…”