Skin-like ferroelectret films for advanced robotics, human-machine interfaces

Advanced robots and next-generation human-machine interfaces require advanced sensors to interact with their users and the world around them. Mechanical stimuli, such as touch, pressure, and sound, are some of the most important sources of sensory information, making the development of electromechanical sensors crucial.

Ruan et al. developed a polypropylene ferroelectret film with a skin-like texture to act as such a sensor. Their material is thin, lightweight, stretchable, and exhibits impressive piezoelectric capability.

Ferroeletrets are ideal electromechanical sensors thanks to their strong piezoelectric activity, low acoustic impedance, and flexibility. Because ferroeletrets can be made from a variety of polymers, they are potentially more cost-effective and easier to manufacture than conventional piezoelectric materials.

The authors developed their ferroelectret film to mimic the surface geometry and cellular bulk structure of human skin. This design allows for several unique properties, meeting or exceeding the capabilities of the largest sensory organ in the human body.

“The specific texture provides excellent mechanical properties, strong capability for multimodal reception, and specific functions involving receiving and emitting audio and ultrasonic waves which are beyond the capability of natural skin,” said author Xiaoqing Zhang.

The team will continue to refine their fabrication process and adapt it for industrial manufacturing.

“In the next step, we plan to further improve the uniformity of the ferroelectret films by replacing the manual fusion bonding with a controllable machine and developing various sensors and actuators,” said Zhang. “Because this preparation process is very simple and compatible with industry, we hope such an advanced piezoelectric film can be mass-produced in the near future.”

Source: “Ultralight and sensitive ferroelectret films with a human skin-like texture,” by Zehai Ruan, Qianqian Hu, Mi Zhang, Weilin Liu, Guodong Zhu, Min Chen, and Xiaoqing Zhang, Applied Physics Letters (2023). The article can be accessed at https://doi.org/10.1063/5.0148666 .

This paper is part of the Energy Conversion and Storage in Functional Dielectrics Collection, learn more here .