High-performance graphdiyne-based electrochemical actuators

TLDR

Electrochemical actuators that convert electrical energy to mechanical energy are crucial for AI, yet their efficiency remains below 1 % because electrode microstructures lack active units and assemblies cannot reveal intrinsic properties. We demonstrate that a graphdiyne‑based actuator achieves high performance by exploiting an alkene–alkyne complex transition, confirmed via in situ sum frequency generation spectroscopy. The graphdiyne actuator delivers a 6.03 % electro‑mechanical transduction efficiency, an 11.5 kJ m⁻³ energy density comparable to skeletal muscle, operates from 0.1 to 30 Hz with stable performance over 100 000 cycles, and its high efficiency is attributed to the alkene–alkyne complex transition.

Abstract

Abstract Electrochemical actuators directly converting electrical energy to mechanical energy are critically important for artificial intelligence. However, their energy transduction efficiency is always lower than 1.0% because electrode materials lack active units in microstructure, and their assembly systems can hardly express the intrinsic properties. Here, we report a molecular-scale active graphdiyne-based electrochemical actuator with a high electro-mechanical transduction efficiency of up to 6.03%, exceeding that of the best-known piezoelectric ceramic, shape memory alloy and electroactive polymer reported before, and its energy density (11.5 kJ m −3 ) is comparable to that of mammalian skeletal muscle (~8 kJ m −3 ). Meanwhile, the actuator remains responsive at frequencies from 0.1 to 30 Hz with excellent cycling stability over 100,000 cycles. Furthermore, we verify the alkene–alkyne complex transition effect responsible for the high performance through in situ sum frequency generation spectroscopy. This discovery sheds light on our understanding of actuation mechanisms and will accelerate development of smart actuators.