Whisker Sensor With Extended Measurement Range Through Jamming Effects Using 3D-Printed Tetrapod Particles

Whisker sensors, typically fabricated by casting soft polymers, have a measurement range determined by the mechanical properties of the soft polymer used, specifically, its Young's modulus. Traditional whisker sensors have fixed stiffness after fabrication, which limits their measurement range. However, this study introduced a sensor that integrates a jamming actuator with a whisker sensor, allowing for adjustable stiffness. This adjustment not only enables high sensitivity within a specific measurement range but also expands the measurable range. Moreover, to enhance the jamming effect, tetrapod-shaped particles, which exhibit the highest friction, were fabricated using 3D printing, significantly improving the measurement range. Additionally, four channels were strategically placed at the shell edges, within which materials with Young's moduli higher than that of polydimethylsiloxane (PDMS) could be filled, allowing for an adjustable overall stiffness. When no vacuum pressure was applied, the whisker sensor filled with tetrapod particles was able to measure forces with a sensitivity of approximately 93 mm/N in the range of 0-70 mN. When a vacuum pressure of -50 kPa was applied, the sensor could measure forces with a sensitivity of around 82 mm/N in the range of 70-140 mN. Under a vacuum pressure of -100 kPa, the sensor could measure forces with a sensitivity of approximately 65 mm/N in the range of 140-220 mN. This innovation enables the selective expansion of the sensitivity and measurement range, which were previously difficult to achieve, showcasing new possibilities for jamming actuators and their potential use in exploration environments requiring a wide measurement range.[2024-0099]