Magnetostrictive chain-linked tactile sensors based on controllable discharge-triggered sensitivity enhancement effect.

In this work, we developed a novel 'magnetically-induced alignment combined with local field discharge sensitivity enhancement' strategy to improve the sensitivity of conductive particle-filled piezoresistive sensors. The formation of 'particle-microcavity' chain structures within the composite results in the change of the dominant piezoresistive response mechanism from tunnel resistance to dynamic contact resistance. Therefore, the piezoresistive sensors exhibit a significant sensitivity enhancement from 0.102 kPa-1-0.371 kPa-1, representing a 264% increase compared with the base sensor. These sensors exhibit a low detection limit of 490 Pa, a rapid response time of 266 ms, and excellent long-term stability (maintaining stable performance after 6000 cycles of pressure loading at 5 kPa), along with good process consistency. Furthermore, these sensors are tested for tactile perception in multiple human body regions (including finger grasping, wrist bending, and plantar force monitoring), and confirm that the sensitivity-enhanced sensor can accurately detect tiny forces.