Design and implementation of time-delay switch triggered by inertia load

This study extends the concept of capillary valve to realize a micro time-delay switch for safety and arming application. The presented device consists of working fluid (Glycerol), micro capillary valve with required time-delay mechanism design, and sensing electrodes. Thus, the delay time could be easily changed by (1) varying the geometry design of valve angle β and the neck-width w, and (2) selecting the working fluid. The design could also be easily changed for applications of different inertia force. Simulation shows the time-delay of m-second to few seconds can be easily achieved and adjusted by the presented design. This study has successfully fabricated the proposed time-delay switch. Measurements show the switch with Glycerol working fluid have 4.1 to 10.9 seconds delay time by varying the design parameters from β = 30° and w = 1000 μm to β = 60° and w = 500 μm.