Movie S6. Application on a robotic fin
2.5.2 Fabric-based finger
We further fabricate a soft fabric-based pneumatic actuator \cite{Feng.2021,Ge.2020} for use in rehabilitation and assistive exoskeletons to examine the broad potential of IEAR for different materials and actuator types (Figure 4g-i, Supplementary Note 6, and Movie S7). This fabric-based actuator (10.2 g) comprises a flexing chamber and an extending chamber, and it is worn on a silicone hand to assist the finger motion. Experimental results show that the actuation frequency with our IEAR mechanism is nearly 2× that with DIDO for the full range of pressures, while the energy consumption per cycle only takes about half that with DIDO (Figure 4h and i). For example, when \(p_{high}\) =75 kPa, the actuation frequency and energy consumption with DIDO are 0.33 ± 0.01 Hz and 11.70 ± 0.28 mWh·cycle-1. However, the corresponding actuation performances with IEAR are 0.62 ± 0.02 Hz (87.9%↑) and 5.99 ± 0.20 mWh·cycle-1 (48.8%↓). In hand rehabilitation, especially assistance, an actuation speed of faster than 0.5 Hz is important for activities of daily living (ADLs) \cite{Polygerinos.2015}, such as grasping an apple, operating a ball or drinking water. Besides, the comparisons of the supplied air pressure \(p_{tank}\) and the system power also demonstrate the advantages of our IEAR over the traditional DIDO (Figure S8d-f). Except for the fabric-based finger, an extensive application on a fiber-reinforced silicone actuator also verifies the effectiveness of IEAR in improving actuation speed and energy efficiency (Figure S9a-c and Supplementary Note 7).