Two-Dimensional Nanosheets-Based Soft Electro-Chemo-Mechanical Actuators: Recent Advances in Design, Construction, and Applications

Abstract

Soft electro-chemo-mechanical actuators have received enormous interest in biomimetic technologies, wearable electronics, and microelectromechanical systems due to their low voltage-driven large deformation, fast response, high strain, and working durability. Two-dimensional (2D) nanosheets, which can highly promote ion-induced micromotion to macrodeformation, have outstandingly been used as prime actuator electrodes because of their ordered microstructures, tunable interlayer spaces, controllable electrochemical activities, and excellent electrical and mechanical properties. Here, this review primarily focuses on the recent advances in key 2D electro-chemo-mechanical actuator electrodes, including graphene, MXenes, graphitic carbon nitride, molybdenum disulfide, black phosphorus, and graphdiyne. Various synthetic strategies of electrode design, such as microstructural architecture, active-site regulation, and channel construction, for achieving high ionic kinetic transport, charge storage, and electrochemical-mechanical performances are discussed. The advanced structures with diverse building principles that provide ordered and active ionic pathways for high actuation speed and strain are emphasized. Furthermore, the innovative applications of electro-chemo-mechanical actuators toward biomimetic robots and smart devices are highlighted. Finally, the current challenges and future perspectives are also proposed. The aim of this review is to provide the guiding significance for scientific researchers and industrial engineers to design higher performance next-generation electro-chemomechanical actuators.

Electroactive nano-Biohybrid actuator composed of gold nanoparticle-embedded muscle bundle on molybdenum disulfide nanosheet-modified electrode for motion enhancement of biohybrid robot

“…The electrochemical actuator is driven by shrinkage and expansion due to ion intercalation between layered structures of MoS 2 NSs [ 21 , 28 , 29 ]. The electrochemical actuator generally operates based on an acidic solution, but the properties of fabricated MoS 2 NS-modified Au-coated PI electrode were verified using 20 mM PBS electrolyte to connect to the HA@GNPs-embedded muscle bundle.…”

Soft Actuators Based On Carbon Nanomaterials

“…[78] Compared to traditional iEAPs with noble metal electrode, those exploring carbon nanomaterials as electrodes showed attractive performances, which can be attributed to an increasing specific capacitance and power density, stronger interface coupling as well as a resistance of surface cracking of the electrode materials. [79] Ru et al fabricated iEAP actuators with nanoporous CNT film as the electrode and Nafion/EmimBF 4 electrolyte layer as the intermediate layer and reported a promoted mass migration between the electrode layer and electrolyte layer, and an increased response speed and bending degree. [80] Lu et al designed PVDF/BmimBF 4 electrochemical actuator with RGO/MWCNT all-carbon electrode.…”

Ultrafast, Light, Soft Martensitic Materials

“…Dynamic materials, a class of engineering materials whose properties can vary in space and time, are the key components in smart devices that are capable of translating electrical, chemical, mechanical, or other stimuli such as light, pH, temperature, and humidity into a mechanical response by reconfiguration or actuation. [1][2][3][4][5][6][7][8][9][10] Their chemical structures and engineering design can vary greatly, and are matched to their natural time of response and related characteristics such as operation frequency, efficiency, and cyclability. [37,40,41] Traditionally, phase transitions in organic crystals have been implicitly assumed to be slow because their structural units are connected by intermolecular interactions that are weaker than the metallic bonds in metals and alloys.…”