Multistable wireless micro-actuator based on antagonistic pre-shaped double beams

• Published in: Smart materials and structures Vol. 24; no. 7; pp. 75028 - 7
• Main Authors: Liu, X, Lamarque, F, Doré, E, Pouille, P
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.07.2015
• Subjects: Asymmetry; Beams (structural); Bistability; bistable pre-shaped beam; contactless actuation; Density; Fiberboard; Lasers; MDF; micro-actuator; multistable; shape memory alloy (SMA); Shape memory alloys
• ISSN: 0964-1726; 1361-665X
• DOI: 10.1088/0964-1726/24/7/075028

This paper presents a monolithic multistable micro-actuator based on antagonistic pre-shaped double beams. The designed micro-actuator is formed by two rows of bistable micro-actuators providing four stable positions. The bistable mechanism for each row is a pair of antagonistic pre-shaped beams. This bistable mechanism has an easier pre-load operation compared to the pre-compressed bistable beams method. Furthermore, it solves the asymmetrical force output problem of parallel pre-shaped bistable double beams. At the same time, the geometrical limit is lower than parallel pre-shaped bistable double beams, which ensures a smaller stroke of the micro-actuator with the same dimensions. The designed micro-actuator is fabricated using laser cutting machine on medium density fiberboard (MDF). The bistability and merits of antagonistic pre-shaped double beams are experimentally validated. Finally, a contactless actuation test is performed using 660 nm wavelength laser heating shape memory alloy (SMA) active elements.