Functional electronics has promising applications, including highly advanced human-interactive devices and healthcare monitoring. Here, we present a unique printable micron-scale cracked strain sensor (PMSCSS), which is bioinspired by a spider's crack-shaped lyriform slit organ. The PMSCSS is fabricated by a facile process that utilizes screen-printing to coat carbon black (CB) ink onto a paper substrate. With a certain bending radius, a cracked morphology emerged on the solidified ink layer. The working principle of the PMSCSS is prominently attributed to the strain-dependent variation in resistance due to the reconnection-disconnection of the crack fracture surfaces. The device shows appealing performances, with superfast response times (∼0.625 ms) and high sensitivity (gauge factor = 647). The response time surpasses most recent reports, and the sensitivity is comparable. We demonstrate the application of the PMSCSSs as encoders, which have good linearity and negligible hysteresis. Also, the sensor can be manipulated as a vibration detector by monitoring human-motion disturbances. According to the sensory information, some details of movements can be deduced.

Integrated sensor–actuators with exciting functionalities, such as action self‐sensing, position self‐sensing, posture self‐sensing, or active sensing, are promising for applications in biomedical device, human–machine interaction, intelligent self‐protection devices, and humanoid robots. Despite recent progress, it remains challenging to achieve a macroscopical integrated sensor–actuator in a material system with microstructures. To address this critical challenge, a 4D printing bioinspired microstructure strategy is reported to design a high‐performance integrated sensor–actuator capable of simultaneous actuation and sensation. Decoupled thermal stimulation and strain sensation is achieved by combining nanocarbon black/polylactic acid composites with bioinspired gradient microgap structures. As a result, printed integrated sensor–actuators can actively touch objects triggered by thermal stimulation and self‐sense the touching state through the resistance change. It is anticipated that the basic design principle underlying this behavior can be used to develop integrated sensor–actuators of various shapes and functionalities to meet desirable applications.

No abstract

In the field of engineering, a crack, inducing enormous mechanical energy concentration at a tip, is considered a typical kind of defect. However, it is found that, to maximize the sensitivity of slit-based mechanoreceptors, the near-tip stress field of "risky" crack-shaped slits is ingeniously used by scorpions to precisely detect the cyclic loads acting on walking legs without the crack nucleation from the flaw-like tip. As a sophisticated biological mechanoelectrical transducing microsystem, the mechanoreceptor can effectively collect mechanical energy contained in the mechanical signal through antifracture slit allays and then convert the mechanical energy into electrical energy through mechanosensory neuron. The highly efficient mechanoelectrical energy conversion mechanism is theoretically analyzed and experimentally verified in a bioinspired artificial mechanoreceptor. The results demonstrate the potential of basic "design" principles, underlying the slit-dependent mechanoreceptor, for maximizing the electromechanical conversion efficiency of the industrial mechanoelectrical transducing microsystem such as nanogenerators, ultrasensitive mechanical sensors, self-powered portable, and wearable electronics.