Electro-thermally driven biaxial bending artificial muscle based on oriented graphite nanoplate nanocomposite/polyimide complex structure

•The GNP/PI bi-layer films are fabricated by a simple and cost-effective approach which have light weight and large deformation.•Driven by the voltage of 10 V, the artificial muscle is able to reversibly reach a shrinkage rate of 11% and a maximum lifting height of 2.5 cm with the object weight of 5.0 g.•Based on the GN/PI bi-layers, a walking robot has also been designed to achieve a large displacement under the voltage of about 20.0 V. In recent years, artificial muscle is of great research interest due to its promising application. However, low deformation, complicated fabrication process, and high cost hinder their development. Herein, electro-thermally driven biaxial bending artificial muscle based on oriented graphite nanoplate nanocomposite (GN)/polyimide (PI) complex structure is successfully fabricated by cost-effective process utilizing coefficient of thermal expansion difference between them. GN/PI bi-layer films were further assembled and packaged into multi-unit biaxial bending actuator, which could extend and contract like artificial muscle. The unique characteristics of large deformation, easy control, low cost and simple fabrication process distinguish the GN/PI bi-layer based artificial muscle from others. Driven by the voltage of 10 V, the artificial muscle could reversibly reach a shrinkage rate of 11% and a maximum lifting height of 2.5 cm with the object weight of 5.0 g. Moreover, a walking robot has also been designed to achieve a large displacement.