Fig. 3: Time-lapse images showing the valve in action.
From: Thermally-actuated microfluidic membrane valve for point-of-care applications
a The valve is turned on at t = 0 s when the water–dye interface is roughly in the middle of the channel. b–d The oil in the valve heats up, expands and blocks the flow in the dye channel. The interface gradually recedes to a bare minimum
