An artificial muscle capable of shape programmability, deformation-locking capacity without needing continuous external energy, and self-sensing capability is highly desirable yet challenging in applications of reconfigurable antenna, deployable space structures, etc. Inspired by coupled behavior of the muscles, bones, and nerve system of mammals, a multifunctional artificial muscle based on polydopamine-coated liquid crystal elastomer (LCE) and low–melting point alloy (LMPA) in the form of a concentric tube/rod is proposed. Thereinto, the outer LCE is used for reversible contraction and recovery (i.e., muscle function); the inner LMPA in the resolidification state is adopted for deformation locking, and that in the melt state is adopted for angle variation monitoring by detecting resistance change (i.e., bones and nerve functions, respectively). The proposed artificial muscle demonstrates multiple performances, including controllable bending angle, position, and direction; deformation locking for supporting heavy objects; and real-time monitoring of angle variation, which also provides a straightforward and effective approach for designing soft devices.
Human-like tactile perception is critical for promoting robotic intelligence. However, reproducing tangential “sliding” perception of human skin is still struggling. Inspired by the lateral gating mechanosensing mechanism of mechanosensory cells, which perceives mechanical stimuli by lateral tension–induced opening-closing of ion channels, we report a robot skin (R-skin) with mechanically gated electron channels, achieving ultrasensitive and fast-response sliding tactile perception via pyramidal artificial fingerprint-triggered opening-closing of electron gates (E-gates, namely, customized V-shaped cracks within embedded mesh electron channels). By imitating cytomembrane to modulate membrane mechanics, local strain is enhanced at E-gates to effectively regulate electron pathways for high sensitivity while weakened at other positions to suppress random cracks for robust stability. The R-skin can directly recognize ultrafine surface microstructure (5 μm) at a response frequency (485 Hz) outshining humans and achieve human-like sliding perception functions, including dexterously distinguishing texture of complex-shaped objects and providing real-time feedback for grasping.
Flexible sensor arrays have attracted extensive attention in human‐computer interaction. However, realizing high‐performance sensor units with programmable properties, and expanding them to multi‐pixel flexible arrays to maintain high sensing consistency is still struggling. Inspired by the contact behavior of octopus antenna, this paper proposes a programmable multistage dome structure‐based flexible sensing array with robust sensing stability and high array consistency. The biomimetic multistage dome structure is pressurized to gradually contact the electrode to achieve high sensitivity and a large pressure range. By adjusting the arrangement of the multistage dome structure, the pressure range and sensitivity can be customized. More importantly, this biomimetic structure can be expanded to a multi‐pixel sensor array at the wafer level with high consistency through scalable and high‐precision imprinting technologies. In the imprinting process, the conductive layer is conformally embedded into the multistage dome structure to improve the stability (maintain stability over 22 000 cycles). In addition, the braced isolation structure is designed to effectively improve the anti‐crosstalk performance of the sensor array (crosstalk coefficient: 26.62 dB). Benefitting from the programmable structural design and high‐precision manufacturing process, the sensor array can be customized and is demonstrated to detect human musculation in medical rehabilitation applications.
Artificial dry adhesives have exhibited great potential in the field of robotics. However, there is still a wide gap between bioinspired adhesives and living tissues, especially regarding the surface adaptability and switching ability of attachment/detachment. Here, we propose a sensing-triggered stiffness-tunable smart adhesive material, combining the functions of muscle tissues and sensing nerves rather than traditional biomimetic adhesive strategy that only focuses on structural geometry. Authorized by real-time perception of the interface contact state, conformal contact, shape locking, and active releasing are achieved by adjusting the stiffness based on the magnetorheological effect. Because of the fast switching of the magnetic field, a millisecond-level attachment/detachment response is successfully achieved, breaking the bottleneck of adhesive materials for high-speed manipulation. The innovative design can be applied to any toe’s surface structure, opening up a previously unknown avenue for the development of adhesive materials.
Tunable structural color has many potential applications in artificial camouflage, mechanical sensors, etc. Despite the extensive efforts to develop efficient tunable structural color, there is still a wide gap between the existing “passive” tuning methods and the “active” strategy found on organisms such as chameleons that can change color according to the environment. Inspired by the active tunable color system of chameleons, we propose a smart skin comprising a nanoscale hole array of photonic crystals, carbon nanotube coatings, and liquid crystal elastomers, to integrate multiple functions, i.e., structural color tunability, sensing, and actuation, in one structure. The smart skin was further coupled with an image acquisition unit (which mimics eyes to obtain colors from the environment) and a controller (which mimics the brain to process the signals transmitted from the image acquisition unit to the smart skin), to construct an active tunable structural color system. The proposed system autonomously modulates the color according to the environmental color. To validate the color tuning, color scanning from red to green to blue or vice versa is demonstrated in this work, which could certainly open up new paths to create active tunable structural color systems, and thus, push the development of structural color-based devices and systems.