In our IEAR mechanism, the working state of the air pump is independent of these specific actuation processes (Figure 1a). When the pressure in the air tank \(p_{tank}\) is less than a threshold \(p_{tank-low}\) , the air pump starts to work. Once \(p_{tank}\) is more than \(p_{tank-high}\) , the air pump turns off. The difference between \(p_{tank-high}\) and \(p_{tank-low}\) is the pressure tolerance for pump resting. Notably, we generally set the gauge pressure \(p_{tank-low}\) and \(p_{tank-high}\) as 120 kPa and 125 kPa, respectively.