Dual-mechanism layered ionic skin: For quick touch position sensing and high-precision touch intensity detection

Area of Science:

• Materials Science
• Robotics
• Human-Computer Interaction (HCI)

Background:

• High-precision integrated detection of touch position and intensity is critical for advanced intelligent sensing technologies in robotics and HCI.
• Existing array-type sensors suffer from structural complexity, while current layered designs struggle with signal crosstalk due to single-mechanism sensing for both position and intensity.
• There is a need for streamlined sensor architectures capable of simultaneous, high-precision detection of both touch location and force.

Purpose of the Study:

• To develop a novel dual-mechanism layered ionic skin (DM-LIS) that overcomes the limitations of existing sensors for integrated touch detection.
• To enable synchronous and high-precision detection of both the position and intensity of mechanical stimuli.
• To provide a workable technical solution with substantial potential applications in high-precision HCI.

Main Methods:

• A dual-mechanism layered ionic skin (DM-LIS) was designed, integrating a lower capacitive sensing layer (CSL) and an upper resistive positioning layer (RPL).
• The CSL utilizes an ionic gel-infused porous sponge for high-precision touch intensity detection via a dual-capacitor structure.
• The RPL employs graphite conductive adhesive on a sandpaper microstructure for touch position recognition, sharing a sandpaper substrate with the CSL for design streamlining.

Main Results:

• The DM-LIS demonstrated a touch position reaction time of 18 ms with a resolution of 5 mm.
• The sensor achieved a touch intensity detection sensitivity of 0.356 kPa⁻¹ using its dual detection mechanism.
• An intelligent keyboard built with the DM-LIS successfully drove game blocks with precise responses in Tetris, validating synchronous and high-precision detection capabilities.

Conclusions:

• The developed dual-mechanism layered ionic skin offers a viable solution for synchronous, high-precision detection of pressing intensity and tactile location.
• The integrated design significantly streamlines device architecture compared to traditional discrete or single-mechanism layered sensors.
• The DM-LIS exhibits significant potential for applications in high-precision human-computer interaction and intelligent robotic systems.