Fig. 1.
Pneumatic inverter and ring oscillator. (A) Normally off elastomeric valve (cross section). The sealed channel is opened when vacuum is applied to deform the valve membrane. (B) Pneumatic inverter gate (Right) is analogous to NMOS inverter (Left). Vdd, voltage supply; GND, ground; VAC, vacuum supply; ATM, atmospheric pressure. (C) Inverter transfer function reveals high nonlinear gain. (D) Ring oscillator circuit is formed by an odd number of inverter gates connected in a closed loop. (E) Video microscopy of valve actuation pattern in ring oscillator (22 ms between frames). (F) Oscillatory waveform of a single valve, captured by measuring the deflection of an incident laser beam. (G) Fourier transform of a 10-min time course. The quality factor Q is ∼100.