Artificial tactile technology based on skin-like sensors is rapidly developing, enabling quick perception of the surrounding environment and interaction capabilities. This technology has enormous application potential in fields such as robotic (especially humanoid robots) tactile perception, embodied intelligence, virtual reality (VR), and wearable devices. Flexible pressure sensors often utilize soft materials to achieve skin-like flexibility; however, the viscoelastic creep of soft materials and the unique ionic leakage issues of ionic gels are challenging to resolve, leading to sensor signal drift and measurement inaccuracies.
Figure 1: Principles, materials, and chemistry of drift-free ionic sensors
Here, we report a design at the molecular level that co-polymerizes a leak-free, creep-free polyelectrolyte elastomer, effectively suppressing signal drift in ionic flexible pressure sensors, resulting in a drift-free ionic electronic flexible pressure sensor. This elastomer consists of two types of chain segments: charged molecular chains with fixed cations to prevent ionic leakage, and neutral chains with high crosslink density to achieve low creep. The results demonstrate that the ionic flexible pressure sensor using this polyelectrolyte elastomer exhibits almost no drift under high static loads (500 kPa, close to its Young’s modulus, with an initial drift rate of 0.01–0.1% min−1 and decreasing to 0.001% min−1 within 10 minutes) over 48 hours of operation, with a drift rate 2-3 orders of magnitude lower than sensors using traditional ionic conductors, enabling stable and precise control in robotic manipulation.
Figure 2: Characterization of polyelectrolyte elastomer properties
The drift-free ionic flexible pressure sensor proposed in this article effectively addresses the common challenge of accurately measuring static pressure in such devices. This technology not only enhances the stability and precision of flexible pressure sensors but also demonstrates its broad application potential in fields such as precise robotic control, providing a novel material and design strategy for the development of high-precision artificial tactile technology.
Figure 3: Perception characteristics of ionic sensorsFigure 4: Drift comparison and drift rates of various ionic sensors
Figure 5: Precise force sensing for stable robotic control★ Source: Research Insights ↑ ★ Please cite the above source↑This article is for informational purposes only and is for reference. If there are issues related to the content, copyright, or other matters, please contact us, and we will address them immediately. If this article is reprinted on any platform, the reprinting party is responsible for the content, and Xiangrun Instruments is not responsible for any secondary dissemination caused by reprinting.