Iontronic graphene tactile sensors (i‐GTS) composed of a top floating graphene electrode and an ionic liquid droplet pinned on a bottom graphene grid, which can dramatically enhance the performance of capacitive‐type tactile sensors, are presented. When mechanical stress is applied to the top floating electrode, the i‐GTS operates in one of the following three regimes: air–air, air–electric double layer (EDL) transition, or EDL–EDL. Once the top electrode contacts the ionic liquid in the i‐GTS, the spreading behavior of the ionic liquid causes a capacitance transition (from a few pF to over hundreds of pF). This is because EDLs are formed at the interfaces between the electrodes and the ionic liquid. In this case, the pressure sensitivity increases to ≈31.1 kPa⁻¹ with a gentle touch. Under prolonged application of pressure, the capacitance increases gradually, mainly due to the contact line expansion of the ionic liquid bridge pinned on the graphene grid. The sensors exhibit outstanding properties (response and relaxation times below 80 ms, and stability over 300 cycles) while demonstrating ultimate signal‐to‐noise ratios in the array tests. The contact‐induced spreading behavior of the ionic liquid is the key for boosting the sensor performance.

中文翻译：

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固定在石墨烯网格上的离子液体的扩散促进了离子型石墨烯触觉传感器的增强灵敏度

提出了一种由顶部浮动石墨烯电极和固定在底部石墨烯网格上的离子液滴组成的离子型石墨烯触觉传感器（i‐GTS），可以显着增强电容式触觉传感器的性能。当对顶部浮动电极施加机械应力时，i‐GTS会以以下三种方式之一运行：空气-​​空气，空气-电气双层（EDL）过渡或EDL-EDL。一旦顶部电极与i‐GTS中的离子液体接触，离子液体的扩散行为就会引起电容跃迁（从几pF到几百pF）。这是因为EDL形成在电极与离子液体之间的界面处。在这种情况下，压力灵敏度增加到≈31.1kPa ^-1轻柔地触摸。在长期施加压力下，电容逐渐增加，这主要是由于固定在石墨烯网格上的离子液体桥的接触线膨胀。这些传感器表现出出色的性能（响应和弛豫时间低于80 ms，并且在300个周期内具有稳定性），同时在阵列测试中展现出最终的信噪比。离子液体的接触诱导扩散行为是提高传感器性能的关键。