Abstract
To realize portable and powerful digital microfluidic systems, mechanical logic controllers are desired. We present a new type of pneumatic gain valves that can readily be 3D integrated to realize multi-stage logic systems. A thin diaphragm with a stiffness-enhancing bump is sandwiched between pressure chambers to switch the output on and off. By tailoring the structure geometry, a 150% pressure gain and a 30 kPa on/off hysteresis have been achieved. As such, the output of one logic device can be boosted to serve as the input for the next stage. 3D multistage digital controllers have been successfully demonstrated.