Flexible and Stretchable Carbon-Based Sensors and Actuators for Soft Robots

Abstract

In recent years, the emergence of low-dimensional carbon-based materials, such as carbon dots, carbon nanotubes, and graphene, together with the advances in materials science, have greatly enriched the variety of flexible and stretchable electronic devices. Compared with conventional rigid devices, these soft robotic sensors and actuators exhibit remarkable advantages in terms of their biocompatibility, portability, power efficiency, and wearability, thus creating myriad possibilities of novel wearable and implantable tactile sensors, as well as micro-/nano-soft actuation systems. Interestingly, not only are carbon-based materials ideal constituents for photodetectors, gas, thermal, triboelectric sensors due to their geometry and extraordinary sensitivity to various external stimuli, but they also provide significantly more precise manipulation of the actuators than conventional centimeter-scale pneumatic and hydraulic robotic actuators, at a molecular level. In this review, we summarize recent progress on state-of-the-art flexible and stretchable carbon-based sensors and actuators that have creatively added to the development of biomedicine, nanoscience, materials science, as well as soft robotics. In the end, we propose the future potential of carbon-based materials for biomedical and soft robotic applications.

Actuation for flexible and stretchable microdevices

“…Flexible and stretchable materials and suitable actuation mechanisms are paramount in soft robotics. 231,232 The actuation should provide the intended dexterity to achieve motions such as extension, contraction, twisting, and bending. 232 Actuation mechanisms such as fluid-driven, 68,233,234 thermal, 72,88 electrical, 225,235,236 and magnetic 113,237,238 have been widely used for soft robotics.…”

3D Printing Bio‐Inspired Micro Soft Robot with Programming Magnetic Elastic Composites

“…So that they are able to change their shapes and forms, squeeze through confined spaces, and manipulate objects dexterously to adapt to different tasks and environments. [2] Elastomeric materials generally include hydrogels, [3][4][5] hyperelastic materials, [6][7][8] dielectric elastomeric materials, [9][10][11] polydimethylsiloxane (PDMS), [12] carbonbased materials, [13][14][15] shape-memory alloys, [16][17][18] shape-memory polymers, [19] and other flexible materials, which are well suited for applications under specific conditions. However, hydrogel and carbon-based materials have poor mechanical properties.…”

Application‐Oriented Modeling of Soft Actuator Ionic Polymer–Metal Composites: A Review

“…[ 3 ] Compared to conventional rigid actuators, soft actuators exhibit remarkable advantages in terms of biocompatibility, portability, and power efficiency, and they provide more precise than hydraulic and pneumatic actuators at subcentimeter scales. [ 4 ] Due to the flexibility and compliance of soft actuators, they are particularly beneficial for physical interaction with fragile objects or living organisms. [ 5 ] Ionic polymer–metal composite (IPMCs) are types of electrically stimulated soft actuators that have lower operating voltage than the safe voltage of the human body, low power density, and relatively high efficiency compared to other actuators (muscles, shape memory alloy, piezoelectric polymer, and hydraulic).…”