Adaptive nanotube networks enabling omnidirectionally deformable electro-driven liquid crystal elastomers towards artificial muscles.

Highlights

1.        Facile strategy to create high-performance electro-driven artificial muscles

2.        Special design of hierarchically structured carbon nanotube network featuring subtle resistance change under omnidirectional stretching.

3.        Combination of omnidirectional stretchability, robust electrothermal actuation, low driving voltage, and powerful mechanical output.

4.        Real-muscle-like morphing intelligence

Abstract

Artificial muscles that can convert electrical energy into mechanical energy promise broad scientific and technological applications. However, existing electro-driven artificial muscles have been plagued with problems that hinder their practical applications: large electro-mechanical attenuation during deformation, high-driving voltages, small actuation strain, and low power density. Here, we design and create novel electro-thermal-driven artificial muscles rationally composited by hierarchically structured carbon nanotube (HS-CNT) networks and liquid crystal elastomers (LCEs), which possess adaptive sandwiched nanotube networks with angulated-scissor-like microstructures, thus effectively addressing above problems. These HS-CNT/LCE artificial muscles demonstrate not only large strain (> 40%), but also remarkable conductive robustness (R/R₀ < 1.03 under actuation), excellent Joule heating efficiency (≈ 233 °C at 4 V), and high load-bearing capacity (R/R₀ < 1.15 at 4000 times its weight loaded). In addition, our artificial muscles exhibit real-muscle-like morphing intelligence that enables preventing mechanical damage in response to excessively heavyweight loading. These high-performance artificial muscles uniquely combining omnidirectional stretchability, robust electrothermal actuation, low driving voltage, and powerful mechanical output would exert significant technological impacts on engineering applications such as soft robotics and wearable flexible electronics.

Existing electro-driven artificial muscles have been plagued with problems that hinder their practical applications: large electro-mechanical attenuation during deformation, high-driving voltages, small actuation strain, and low power density. Here, we created conceptual-new hierarchically structured HS-CNT/LCE composite artificial muscles enabling the unique combination of omnidirectionally-tunable stretchability, stable electro-mechanical actuation during large deformation, low-voltages driving, large actuation strain, powerful actuation, and long-term working stability. In addition, our artificial muscles exhibit real-muscle-like morphing intelligence that enables preventing mechanical damage in response to excessively heavyweight loading. It is anticipated that the development of such HS-CNT/LCE composite artificial muscles would exert significant technological impacts on engineering applications such as soft robotics and wearable flexible electronics.

论文链接：Adaptive nanotube networks enabling omnidirectionally deformable electro-driven liquid crystal elastomers towards artificial muscles