Fig. 4. High-frequency stimuli detection of the RSHTS and RSHTS-based robotic hand to detect impact force, and simulate robot pouring water.
a High-frequency waveforms generated by tuning forks are recorded by the RSHTS attached to the human finger. Other high-frequency waveforms are shown in Supplementary Fig. 19. b The real-time output charge of four piezoelectric capacitors, from which the knock directions can be determined. Here, the positive and negative peaks of C1, C2, C3, and C4 are labeled to binary values of 1 and 0, respectively. Thus, the decimal value of C1C2C3C4 can be used to present the knock directions shown in the table. c A RSHTS-based robotic hand grasps and holds a plastic bottle, into which water drops are added to simulate the scenario of a robot pouring water. Real-time output charge of one piezoelectric capacitor (others shown in Supplementary Fig. 22), from which the motions of the robotic hand catching bottle, grasping bottle, receiving water, and releasing bottle can be identified. The subgraph shows the details of water vibration at a frequency of 3.5 Hz caused by falling droplets.