3D Printing in Hydrogel for Complex WaveguidingPhotothermal Microactuator

Photothermal microactuators are often used as microswitches or microgrippers in micro-electromechanical systems, whereas it is difficult to fabricate three-dimensional microactuators with a high aspect ratio, since the gravity may lead to undesired deformations during printing processes. In this work, we reported a 3D printing / UV curing process flow in the support of a hydrogel to obtain a photothermal microactuator with a high-aspect-ratio polyline waveguiding structure. The waveguiding structure also served as the driving arm. The temperature parameter was investigated by the Finite Element Method while the experiment was carried out to study the temperature and displacement during the laser actuation. A demonstration showed the driving arm achieves a free-end displacement of 133.2 µm driven by 90 mW laser (46.1°C). This study helps obtain waveguiding photothermal microactuators with integrated and more complex multi-dimensional structures.