Movie S5. Experimental verification of IEAR on the Triple Bellows
Compared with the Double Bellows, the Triple Bellows comprises three chambers arranged in an equilateral triangle, while other structural features remain the same (Figure 3a and Figure S4). These three chambers endow the Triple Bellows with two DOFs: bending relative to the ground and rotation above the z-axis (Figure 3b). According to the force equilibrium on these two DOFs, we can establish the dynamic model (Figure 3c and Supplementary Note 3 and 4). For both the DIDO and IEAR mechanisms (Figure 3d, e), the comparative theoretical and experimental results show good agreement with the others (Figure 3f and Figure S7).
We further characterize the actuation frequency and energy consumption per cycle of the Triple Bellows with \(p_{high}\) from 50 kPa to 100 kPa covered. According to Figure 3g, h, the Triple Bellows also achieve high-speed and low-energy actuation with IEAR. Taking \(p_{high}\)=75 kPa as an example, the actuation frequency and energy consumption of DIDO are 0.33 ± 0.01 Hz and 13.50 ± 0.50 mWh·cycle-1, respectively. Through our IEAR mechanism, the actuation frequency is improved to 0.60 ± 0.02 Hz (82.4%↑) while the energy consumption is reduced to 7.06 ± 0.27 mWh·cycle-1 (47.7%↓). The results from changing \(\Delta p\)(5, 10, 15 kPa) again verify the dynamic model of m-SPAs and the ability of our IEAR mechanism to improve actuation speed and reduce energy consumption in various working conditions (Figure S7).