Principle of opto-thermo-mechanical actuation overcoming μN-scale friction force at micro-scales and the experimental demonstrations (IMAGE)
Caption
A, Driving locomotion of a rectangular plate on a frictional surface through excitations of elastic waves by pulsed optical absorption. Table: relationships between motion states of the plate, (instantaneous) effective absorbed light power, friction force and elastic waves. B, Band structure of elastic waveguide modes in a gold plate (width, w = 4 μm; height, h = 60 nm). Insets: modal profiles of fundamental elastic modes at static frequency (arrows specify directions of elastic oscillations). C, Sliding displacement of the contact surface of the gold plate (same as in B; lower panel) in the z-direction driven by a nanosecond optical pulse (upper panel) with frictional sliding resistance Fslide = 2.7 μN. D, Stabilized sliding displacement as a function of sliding resistance, Fslide. E, Sketch of the observed spiral motion experimentally. F, Temporal sequencing of optical images of a hexagonal gold plate spirally moving around a micro-fiber. The fiber has a diameter of 2 μm and the side length and the thickness of the plate are 27.72 μm and 30 nm, respectively. G, Cosine of rotation angle Φrot (upper panels), translation displacement (lower panels) as functions of time for gold plates with hexagonal, circular, and rectangular base shapes. All scale bars represent 15 μm. The used super-continuum laser pulses have 6.8-mW average power, 3-ns temporal width and 6.13–kHz repetition rate.
Credit
by Weiwei Tang, Wei Lv, Jinsheng Lu, Fengjiang Liu, Jiyong Wang, Wei Yan, and Min Qiu
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Credit must be given to the creator.
License
CC BY