Achieving Ultrasensitivity and Long-Term Durability Simultaneously for Microcantilevers Inspired by a Scorpion's Circular Tip Slits.

Microcantilevers are one of the most essential sensitive elements for various mechanical sensors. Their sensing performance determines the index level of a series of sensors. To date, the long-standing trade-off between ultrasensitivity and long-term durability of microcantilevers still remains a challenge. In nature, scorpions can sense vibrations as low as 10 nm amplitude through their circular tip slits sensilla. Such slit sensilla embedded in the exoskeleton of walking legs endure the compressing and stretching of every movement without spontaneous fracture failures. Here, we focused on the structural design of the circular tip slits which concentrate stress effectively and disperse energy smoothly, with the result that the microcantilevers are ultrasensitive and durable simultaneously in a single element. We devised a reproducible circular tip slits cantilever with enhanced sensitivity and ultralow detection limits to monitor 7 nm amplitude vibrations. The sensor possessed excellent durability and remained highly consistent with the correlation coefficient of nearly 0.999 over 100 000 cycles. Furthermore, the circular tip slits cantilever could precisely sense diverse subtle mechanical signals and exhibited potential applications in monitoring respiratory patterns. The simple geometric design can be easily manufactured on various sensory materials for applications requiring ultrahigh sensitivity and long-time durability.