Laser-Induced Graphene Tapes as Origami and Stick-On Labels for Photothermal Manipulation via Marangoni Effect

Direct light-to-work conversion enables remote actuation through a non-contact manner, among which the photothermal Marangoni effect is significant for developing light-driven robots because of the diversity of applicable photothermal materials and light sources, as well as the high energy conversion efficiency. However, the lack of nanotechnologies that enable flexible integration of advanced photothermal materials with actuators of complex configurations significantly restricts their practical applications. In this paper, laser-induced graphene (LIG) tape is reported as stick-on photothermal labels for developing light-driven actuators based on the Marangoni effect. With the help of direct laser writing technology, graphene patterns with superior photothermal properties are prepared on the PI tape. The patterned LIG tape can be stuck on any desired objects and generates an asymmetric photothermal field under light irradiation, forming a photothermal Marangoni actuator. Additionally, the PI tape with LIG patterns can be folded into 3D origami actuators that permit photothermal Marangoni actuation including both translation and rotation. The graphene-based photothermal Marangoni actuators feature biocompatibility, which is confirmed by MDA-MB-231 cells proliferation experiments. Owing to the excellent photothermal property of LIG patterns, the as-produced photothermal actuators can be manipulated by a variety of light sources, holding great promise for developing light-driven soft robots.