## 4 Applications
### Soft Robotics  
Since their inception, robots have become indispensable in various sectors, including manufacturing, space exploration, biotechnology, and agriculture, due to their advanced technologies. However, traditional rigid robots, typically constructed from steel, face challenges such as the need for advanced protection, heavy weight, and limited maneuverability and adaptability. These limitations have spurred the exploration of novel materials, leading to the rise of soft robotics, which aims to mimic human behavior and overcome the constraints of conventional robots [29]. Soft robots are crafted from materials like rubber, polymers, and silicon, offering advantages such as lightweight, cost-effectiveness, high flexibility, and mechanical compliance. These attributes enable soft robots to excel in applications where rigid robots fall short, such as drug delivery, search and rescue, and human assistance. Figure 28: (**a**) Illustration of wearable touch, tape, and flex sensor using SMP-AgNWs composite. Reproduced with permission from ref. [292]. Copyright 2022 American Chemical Society. (**b**) The current signals and photos (inset) of the composite sensor while detecting finger bending. Reproduced with permission from ref. [297]. Copyright 2022 Elsevier. (**c**) 4D-printed tactile sensor (4 DPS) tested through the application on both spherical dome and saddle surfaces. Reproduced with permission from ref. [183]. Copyright 2023 Elsevier. (**d**) Schematic and experimental demonstration of the application of the nanocomposite in high-temperature warning devices. Reproduced with permission from ref. [236]. Copyright 2022 John Wiley and Sons. (**e**) Optical image of the conductive SMPC tape circuit used to light an LED. Reproduced with permission from ref. [304]. Copyright 2021 Springer Nature. (**f**) Photographic illustration of unpressed and patterned CNC-SMP and GE-SMP for optical anti-counterfeiting. Reproduced with permission from ref. [306]. Copyright 2023 John Wiley and Sons. The shape-memory gripper, a straightforward soft robot, performs gripping and lifting actions through programmed bending and recovery behavior facilitated by SMPCs. [PERSON] et al. engineered a light-activated, 3D-printed morphing structure using AuNPs embedded in acrylate-based SMPs, demonstrating exceptional gripping capabilities [89]. Upon brief light exposure, the gripper initiated a return to its original shape, effectively securing a screw in an upward motion, highlighting its potential as a remotely activated actuator for soft robotics that responded to visible light (Figure 29a). [PERSON] et al. enhanced the NIR light and magnetic response of SMP nanocomposites by incorporating Fe\({}_{3}\)O\({}_{4}\) NPs into a \"hydrogen bonding-metal-phenolic\" sacrificial network, aiming at applications in hazardous chemical operations [307]. The engineered nanocomposites demonstrated exceptional SMEs, facilitating shape programming, folding, and gripping actions crucial for soft robotics in chemical engineering. Under external stimuli, these soft robots performed precise and controlled movements, enabling the sequential addition of different chemicals within a reaction setup, as illustrated in Figure 29b. The durable shape-memory performance across multiple cycles underscores the potential of soft robots to mitigate operator risks in dangerous chemical experiments through remote control. Utilizing 3D printing technology and inspired by plant climbing mechanisms, they also designed a thermos-responsive soft gripper by incorporating CNFs into a polycarbonate (PCL)/poly(butylene adipate-co-terephthalate) matrix [213]. The composite exhibited pre-programmed spiral structures to emulate vine transformation behaviors from straight to spiral forms during climbing. These self-deforming structures, designed with top filling angles of 45\({}^{\circ}\) and 0\({}^{\circ}\), mimic the natural mechanism of plants for wrapping around objects.