Supplementary Materials

Highly stretchable electroluminescent skin for optical signaling and tactile sensing

C. Larson, B. Peele, S. Li, S. Robinson, M. Totaro, L. Beccai, B. Mazzolai, R. Shepherd

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

Download Supplement
  • Materials and Methods
  • Supplementary Text
  • Figs. S1 to S7
  • Table S1
  • Reference (33)
  • Captions for Movies S1 to S3
  • Captions for Data Tables S1 to S11
Data Tables S1 to S11
Data S1: Capacitance vs. uniaxial stretch (Fig. 2B)
Data S2: HLEC illuminance vs. uniaxial stretch (Fig. 2C)
Data S3: Capacitance vs. biaxial stretch (Fig. S2)
Data S4: Capacitance change from finger press (Fig. 4C)
Data S5: Change in capacitance vs. applied pressure (Fig. 4D)
Data S6: Capacitance vs. actuation amplitude (Fig. 4B)
Data S7: Capacitance vs. actuation amplitude for various system states (Fig. S5)
Data S8: Resistance vs. stretch (Fig. S1)
Data S9: HLEC illuminance vs. applied voltage (Fig. S3)
Data S10: Stress vs. stretch ratio for the HLEC device and its constituent layers (Fig. 1C)
Data S11: Strain measurements of the illuminated HLEC vs. engineering strain (Fig. 2A)

Images, Video, and Other Other Media

Movie S1
A hyperelastic light-emitting capacitor (HLEC) is uniaxially stretched to >480%. The HLEC consists of five layers: electroluminescent ZnS particles are embedded in a 1 mm thick silicone sheet with a hydrogel electrode on both sides and an outer layer of silicone to provide structure and electrically insulate the device. An AC voltage (2.5 kV at 700 Hz) is applied to the two electrodes, causing the ZnS particles to emit light. This HLEC consumes 0.2 W and has an illuminated region measuring 4 cm by 5 cm in the undeformed state.
Movie S2
A multi-pixel display with a grid of 64 HLECS is fabricated using replica molding. The silicone encapsulation electrically insulates the display so that it can be safely handled while operated at an AC voltage of 2.5 kV. The highly deformable display is stretched, rolled, folded and conformed to the tip of a finger. Each pixel measures 4 mm.
Movie S3
Three HLEC panels are integrated into a soft robot measuring 15 cm in length. The robot consists of a silicone body with three internal chambers. These pneumatic chambers are pressurized in sequence to create a crawling gait, moving the robot forward at a speed of ~32 body lengths hr-1. The thickness of the HLEC is decreased as each pneumatic chamber is pressurized, increasing the electric field across the electroluminescent layer. The increased electric field leads to increased illuminance as the inflated panels are 22 inflated. In addition to emitting light, the HLEC panels also serve as sensors for the soft robot. The capacitance of each panel changes as it is deformed. These changes in capacitance allow the robot to sense the actuated state of each pneumatic chamber. The HLEC is also sensitive to tactile inputs, allowing the robot to sense its environment.