Biomimetic actuator crafted from a relaxor ferroelectric polymer nanocomposite

Soft actuators have garnered widespread attention due to their distributed actuation and high error tolerance. However, fabricating biomimetic actuators with small-size, simple structure, low energy consumption, and multifunctionality remains challenging. Here, we present a monolayer nanocomposite achieved by incorporating polymer dots into a polyvinylidene fluoride terpolymer. Through interfacial hydrogen bonding and temperature modulation, a gradient distribution of highly polarized regions is achieved within the nanocomposite. This yields ultrahigh electromechanical performance, with an actuation strain of 14.4% and an output mechanical energy density of 1.92 J cm^-³ at 100 MV m^-¹. Multifunctional soft actuators are formed from this nanocomposite, weighing only 50 mg, and can skillfully imitate both caterpillar crawling and butterfly flight, unlocking the potential for multimodal locomotion. This insect-sized bionic actuator consumes a mere 3-8 mW. The combination of simple architecture and low energy consumption may pave the way for future development of truly bionic soft robots.