Integrated punch card controlled normally-closed valves.
(A) Schematic of normally-closed valves depicting mechanism of operation. (B) 3D printed cantilever beam array with spaced pins (2 mm apart), utilized for implementing 15 independent normally-closed valves. (C, D) Micrograph from video of ten normally-closed valves under operation (side view), all of which are independently actuated based on the punch card tape. (E) Normally-closed valve in action, at a single instance of opening and closing depicting the time duration for a single cycle (0.54 seconds). The image depicts the entire region of PDMS deformation with a completely collapsed channel.