Team at Taiyuan University of Technology develops programmable material

Researchers at Taiyuan University of Technology have developed a programmable, multi-responsive actuator using MXene, a two-dimensional transition metal carbide known for its high electrical and thermal conductivity. This actuator is designed for soft robotic applications and responds to humidity, light, and magnetic fields, enabling complex 3D deformations through controlled micro-ridge orientations and heat-welding techniques.

The actuator comprises a bilayer structure with a micro-ridge-structured MXene film and a paraffin wax (PW)/Fe3O4 composite layer. The MXene layer, which is hydrophilic, absorbs and releases water in response to humidity changes, while the PW/Fe3O4 layer, which is hydrophobic, reacts to heat and magnetic fields. This differential response results in reversible bending and twisting motions.

A key innovation is the introduction of micro-ridge structures on the MXene surface, allowing the researchers to program the deformation pathways of the actuator. This enables the formation of complex shapes such as helices and twists. Additionally, individual actuators can be assembled into larger structures via heat-welding, expanding their potential configurations.

The actuator demonstrated stable performance under various stimuli, including humidity, light, and magnetic fields. It maintained consistent functionality over repeated cycles, indicating durability and interlayer stability. Applications demonstrated by the research team include a biomimetic flower responsive to humidity and light, a spiral gripper capable of lifting heavy objects, and a maze robot that performs coordinated tasks.

This development addresses limitations of existing MXene-based actuators, which typically have simple deformation modes or respond to a single stimulus. The design offers a scalable platform for future soft actuators. The research was supported by several Chinese science foundations and published in the journal Nano Research, a leading publication in nanoscience and nanotechnology.