Driving a micro gel robot with a soft-rigid hybrid structure

Abstract

In recent years, biomimetic robots having soft structures like living organisms have been actively studied. They can move flexibly such as living organisms. The common feature of these robots and many organisms is having not only soft structures but also rigid structures. Therefore, we focused on that soft-rigid hybrid structure has important role in biomimetic robots. However, there are few biomimetic robots having soft-rigid hybrid structure in microscale. Soft-rigid hybrid structure is also important in microscale. For instance, Euglena has cytoskeleton and cell membrane as rigid structures, and flagellum as soft structures. Thus, we aim to fabricate biomimetic microrobot having soft-rigid hybrid structure. In this study, we propose a microrobot having soft-rigid hybrid structure. As hard structures, SU-8 which is hard photoresist is used. As soft structures, bioresist which is a temperature-responsive gel is used. Bioresist swells by absorbing water at lower temperature than 32 °C and shrinks by releasing water at higher than the temperature. The proposed robot is fabricated by using multilayered photolithography processes. We mixed bioresist with graphene as a light absorber to actuate this soft structures by near infrared laser irradiation. We succeeded in fabrication and actuation of the proposed robot by light irradiation.