Z-Shaped Electrothermal Microgripper Based on Novel Asymmetric Actuator

Abstract

Based on a V-shaped microactuator with a pair of beams, modifications were made to the length and width of a microactuator to observe the effects. A theoretical approach and numerical characterization of the modified microactuator were performed. Its performance was compared to a similar microactuator with equal beam widths, and a V-shaped microactuator. The proposed microactuator, fed at 2 V, compared to the V-shaped actuator, showed a 370.48% increase in force, but a 29.8% decrease in displacement. The equivalent von Mises stress level increased (until 74.2 MPa), but was below the silicon ultimate stress. When the modified microactuator was applied to the proposed microgripper, compared to the case using a V-shaped actuator, the displacement between the jaws increased from 0.85 µm to 4.85 µm, the force from 42.11 mN to 73.61 mN, and the natural frequency from 11.36 kHz to 37.99 kHz; although the temperature increased, on average, from 42 °C up to 73 °C, it is not a critical value for many microobjects. The maximum equivalent von Mises stress was equal to 68.65 MPa. Therefore, it has been demonstrated that the new modified microactuator with damping elements is useful for the proposed microgripper of novel geometry, while a reduced area is maintained.

Actuation for flexible and stretchable microdevices

“…For instance, Dai et al 101 chose 1 0 inclination angles for the designed bent-beam actuator and achieved 80.75 μm in-plane displacement with a 4 V input voltage. The configurations of bent-beam actuators include beam-array, 102 cascaded bent-beam, 103 Z-shape beam, 100 and out-of-plane bent-beam. 104 Moreover, bent-beam type actuators can be improved by carefully selecting the number of beams to provide higher displacements while improving the mechanical performance.…”

“…98,99 Geometrical parameters, such as the initial beam inclinations, lengths, and the location of the fixed ends of the beams, determine the motion of the shuttle. 100 Higher inclination angles cause adverse effects on the effective displacements. Therefore, inclination angles should be as low as possible to achieve higher in-plane displacements.…”

An Aluminum Electro-Thermally Actuated Micro-Tweezer: Manufacturing and Characterization

“…Different actuation principles, such as electrostatic [9][10][11], electro-thermal [12][13][14][15][16][17][18][19], piezoelectric [1,5,[20][21][22], shape memory alloys [1,23], electro-magnetic [1,[24][25][26], optical [27,28] and pneumatic [29], are proposed for the control of the micro-tweezers motion. Piezoelectric and electro-thermal actuations are the most dominant in commercialized micro-tweezers.…”