Aphid-Inspired and Thermally-Actuated Soft Gripper Using 3D Printing Technology.

Herein, a thermo-actuated aphid-inspired dry adhesive (TADA) that offers tunable and reversible adhesion is reported. It is easily fabricated through 3D printing using a polylactic acid (PLA) filament and silicone elastomer, avoiding the use of unfavorable methods for micro- and nanofabrication and unwanted particles for actuation. The tunable adhesive system mimics aphid biology to achieve adhesion switchability. Switching between adhesion states is enabled by the thermo-actuated PLA, which has shape memory properties. Additionally, silicone elastomer enables adherence to flat substrates such as glass, silicon wafers, and acrylic plates. The detachment time of the TADA can be controlled by changing the printing layer height, which is a 3D-printing parameter that results in a short detachment time when the printing layer height is small. The adhesion strength is measured by applying different preloads and varying the size of the adhesive area. The reversibility between the adhesion-on and adhesion-off states, revealing good repeatability with similar adhesion strengths is also demonstrated. The TADA has potential applications in transferring silicon wafers. In addition, it can be printed to fit a flat plate of any shape, enabling it to grip the plate stably.