A programmable, gradient-composition strategy producing synergistic and ultrahigh sensitivity amplification for flexible pressure sensing

Abstract Flexible pressure sensors are essential transducers for humanoid tactile perceptions in emerging electronic skins. To date, the long-standing tradeoff between high sensitivities and broad detection ranges still remains a particular concern, and it is increasingly challenging to achieve performance breakthroughs solely relying on conventional structure-based optimization. Herein, a gradient-composition strategy beyond previous structural designs is proposed based on bioinspired, nano-architected ridges. For the first time, the tremendous benefits from the manipulation of localized conductivities, rather than contact topography is validated. By introducing this strategy, an impressive 85-fold enhancement of maximum sensitivity is realized while maintaining a detection range of 330 kPa, which outperforms most of previous counterparts. Based on experiments and a quantitative contact model, a formula G = P:(A∘K) is derived, revealing another advantage of this strategy to be compatible with conventional designs for synergistic sensor improvements. Besides, the programmable feature of the microstructural properties and contact sequences conduces to the tuning of sensor performances. With excellent applicability demonstrated in diverse scenarios, this proposed strategy pioneers a new paradigm for tactile sensing, and may spark plentiful architectural designs to fuel the advancement of electronic skins.