Long throw and rotary output electro-thermal actuators based on bent-beam suspensions

This paper reports on several aspects of the performance and application of bent-beam microactuators. Orthogonal pairs of p⁺ Si cascaded actuators with 500-1000 μm long, 6.5 μm thick beams designed for rotary drives are shown to produce 20-30 μm non-resonant displacement with >150 μN loading at less than 8 V, 300 mW. Inchworm type devices using 500-1500 μm long, 8-14 μm thick bent-beams are shown to produce up to 104 μm displacement against 204 μN loading farce with 250-750 mW DC and pulse actuation. Integrated passive locks reduce standby power to zero. Measured frequency response of bent-beam actuators and refinements in modeling that include non-linear thermal expansion coefficients and buckling are also reported