It is believed that graphdiyne, a newcomer of carbon nanomaterials, can compete in various potential applications with conventional sp 2 hybridized carbon systems, namely fullerenes, CNT, and graphene 34, 35, 36, 37. Graphdiyne, which features assembled layers of sp and sp 2 hybridized carbon atoms, has been proposed to be the most stable carbon allotrope with high π-conjunction, uniformly distributed triangular pores, and tunable electronic properties 30, 31, 32, 33. This is mainly because conventional pure sp 2 carbon-based electrodes, including graphene and carbon nanotube, always lack the active units in nanostructure, and their assembly systems can hardly express the intrinsic properties but mainly rely on ion adsorption for actuation. Owing to these landmark works, various actuators with superior performance have emerged one after another, greatly promoting the development of smart material 24, 25, 26, 27, 28, 29 however, the energy transduction efficiency of these actuators is always lower than 1.0%. The other one, called electrostatic double-layer effect, was proposed for graphene actuator by Rogers 22, 23,] in 2011, who made detailed theoretical calculations to prove its rationality through density functional theory (DFT). In 2003, Wanlin Guo further proved giant C–C bond elongation in response to charge injection into CNT structure using Hartree–Fock and density functional quantum mechanics simulations 20, 21. One mechanism, called the quantum-mechanical effect, was proposed by Baughman in 1999, who reported a CNT actuator with exceptional electrochemical actuation in aqueous electrolyte 4, 19, 20. Hitherto, there are two kinds of electrochemical actuation mechanisms that are widely accepted. Although high-energy-storage electrode materials, especially nanocarbon materials, have emerged one after another, highly electro-mechanical transductive actuators have been seldom reported till now 16, 17, 18.Īs actuation performance is mainly dominated by the electrochemical and electromechanical processes of the electrode layer, figuring out the mechanism and dynamics process in the electrode is essential to developing next-generation actuators with higher performance. Strangely, higher ion storage often leads to higher energy storage capacity of electrodes, but does not always lead to higher actuation performance. As the electromechanical stain of IPMC actuators is generated by the reversible ion intercalation and deintercalation in electrodes, the ion storage capacity of electrodes becomes crucial to actuators 14, 15. Ionic polymer metal composite (IPMC) actuators, also called electrochemical actuators, have emerged as one of the most attractive EAP due to their superior performance and cycling stability under low driving voltage 7, 8, 9, 10, 11, 12, 13. Electroactive polymer (EAP) actuators have become the priority research area of artificial muscles by virtue of their lightweight, scalability, low-power dissipation, quick response, and large deformation 4, 5, 6. This discovery sheds light on our understanding of actuation mechanisms and will accelerate development of smart actuators.īio-inspired artificial muscles, actuated in response to external stimulus, have attracted intensive attention in bionics, including robotics, intelligent sensors, and micro electro-mechanical systems during the past decades 1, 2, 3. Furthermore, we verify the alkene–alkyne complex transition effect responsible for the high performance through in situ sum frequency generation spectroscopy. Meanwhile, the actuator remains responsive at frequencies from 0.1 to 30 Hz with excellent cycling stability over 100,000 cycles. 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). 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. Electrochemical actuators directly converting electrical energy to mechanical energy are critically important for artificial intelligence.
0 kommentar(er)
