Supplementary Materials

Hydraulically amplified self-healing electrostatic actuators with muscle-like performance

E. Acome, S. K. Mitchell, T. G. Morrissey, M. B. Emmett, C. Benjamin, M. King, M. Radakovitz, C. Keplinger

Materials/Methods, Supplementary Text, Tables, Figures, and/or References

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  • Materials and Methods
  • Figs. S1 to S16
  • References
  • Captions for movies S1 to S8

Images, Video, and Other Media

Movie S1
The experimental setup shown in Fig. S5 was used to demonstrate dielectric breakdown through a solid dielectric (PDMS) and through a liquid dielectric (Envirotemp FR3). One T-pin was connected to ground while the other was connected to the high voltage amplifier. Voltage was increased linearly at 0.5 kV/s until dielectric breakdown. Dielectric breakdown through the solid dielectric (PDMS) occurred at 34.3 kV which resulted in permanent damage to the material. Dielectric breakdown through the liquid dielectric (Envirotemp FR3) occurred at 14.7 kV which produced a gas bubble that quickly dissipated and the liquid dielectric returned to its initial insulating state
Movie S2
A single donut HASEL actuator made of Ecoflex 00-30 with an electrode diameter of 1.5 cm was actuated, until dielectric breakdown occurred, at which point the device self-healed and continued to operate. The actuator was activated with a 0.5 Hz reversing square wave with varying amplitudes. Sequences of three breakdown cycles are shown: Cycle 1 â€" 15 kV, 18 kV, breakdown, self-heal Cycle 2 - 15 kV, 17 kV, breakdown, self-heal Cycle 3 â€" 15 kV, 18 kV, 20 kV, 22 kV
Movie S3
A stack of five donut HASEL actuators with an electrode diameter of 2.5 cm was actuated with a 15 kV reversing square wave at 0.5, 5, 10, 15, and 20 Hz.
Movie S4
Two stacks of five donut HASEL actuators were used as a soft gripper which was capable of delicately grasping a fresh raspberry and a raw egg. Each donut HASEL actuator had an electrode diameter of 1.5 cm. Before picking up the raspberry, the HASEL actuators were driven with a 1 Hz, 18 kV reversing square wave to demonstrate the gripping actuation, while an 18 kV DC signal was applied to grip and then transport the raspberry. The HASEL actuators were driven with a 20 kV DC signal to lift the raw egg then voltage was turned off to drop the egg.
Movie S5
HASEL actuators were driven near their resonant frequency which amplified actuation response. A single-unit planar HASEL actuator lifted 250 g. The applied voltage signal was a 4.6 Hz sine wave with three different voltage amplitudes â€" 7, 10, and 13 kV. A twounit planar HASEL actuator lifted 700 g. The applied voltage signal was a 2.7 Hz sine wave with two different voltage amplitudes â€" 9.0 and 14.5 kV.
Movie S6
Six two-unit planar HASEL actuators were arranged in parallel to deliver large actuation force. The HASEL actuators lifted a gallon of water (~ 4 kg) which had been dyed with blue food coloring (McCormick) for visibility. The front view shows actuation of the device with a 2.5 Hz sine wave at an amplitude of 11.5 kV and 12.5 kV. The side view shows the six actuators operating at 2.7 Hz with an amplitude of 9.0 kV. Two planar HASEL actuators were mounted on a single clamp so that only three clamps were used, 45 which when viewed from the side, appears as though only three HASEL actuators were used.
Movie S7
Two self-sensing planar HASEL actuators powered a robotic arm. The ‘driving voltage’ (red plot) shows the combined actuation voltage signal and sensing voltage signal. The ‘sensing signal’ (green plot) is the capacitance measured from the HASEL actuators. The HASEL actuators were connected to ground on one side and to the high voltage amplifier on the other. With the actuation voltage turned off, the arm measured changes in capacitance from the external force of a handshake. A tennis ball (60 g) and baseball (125 g) were used to show a change in capacitance from different loads. The arm was then actuated while holding the baseball. The actuation voltage signal was 1 Hz sine wave. Voltage amplitude started at 12.5 kV, was decreased to 10 kV, then further decreased to 8 kV before being turned off.
Movie S8
Two self-sensing planar HASEL actuators powered a robotic arm. The ‘driving voltage’ (red plot) shows the combined actuation voltage signal and sensing voltage signal. The ‘sensing signal’ (green plot) is the capacitance measured from the HASEL actuators. The HASEL actuators were connected to ground on one side and to the HV amplifier on the other. With the actuation voltage turned off, the arm was manually moved and held at different positions. The change in capacitance from these movements is shown in the green plot.