Bioinspired Rheological Sensing for Robotic Liquid Identification in Sealed Containers via Ultrafast Incipient Slip Detection

Abstract

ABSTRACT The rapid, non‐invasive identification of sealed liquids is crucial for ensuring counter‐terrorism security and improving operational efficiency in various scenarios such as airports and large‐scale events. Existing technologies are limited by invasive procedures or reliance on vision. In this research, we developed a bioinspired iontronic tactile sensor with an interlocked “protrusion‐groove” structure. Its unique biomimetic structure allows for the detection of static pressure and incipient slip within a single device, with a peak sensitivity of up to 1873.83 kPa − 1 in the low‐pressure regime and a slip response time as fast as 46 ms. A robotic fingertip integrated with this sensor can effectively capture the transient signals generated by shaking liquids. Furthermore, by extracting physical features from the signals and applying a Random Forest classifier, we developed a non‐visual liquid identification system that achieves an accuracy of 99.04% ± 0.47% for different liquids. This work provides a practical solution for non‐visual liquid identification and demonstrates a robust approach for enabling robots to achieve multimodal tactile perception.