Bio-inspired Miniature Suction Cups Actuated by Shape Memory Alloy

Wall climbing robots using negative pressure suction always employ air pumps which have great noiseand large volume. Two prototypes of bio-inspired miniature suction cup actuated by shape memory alloy (SMA) are designed based on studying characteristics of biologic suction apparatuses, and the suction cups in this papercan be used as adhesion mechanisms for miniature wall climbing robots without air pumps. The first prototypewith a two-way shape memory effect (TWSME) extension TiNi spring imitates the piston structure of the stalkedsucker; the second one actuated by a one way SMA actuator with a bias has a basic structure of stiff margin, guiding element, leader and elastic element. Analytical model of the second prototype is founded considering theconstitutive model of the SMA actuator, the deflection of the thin elastic plate under compound load and thethermo-dynamic model of the sealed air cavity. Experiments are done to test their suction characteristics, and theanalytical model of the second prototype is simulated on Matlab/simulink platform and validated by experiments