Graphene one-shot micro-valve: Towards vaporizable electronics

One-shot micro-valves are key to applications that require leak-proof sealing of micro-cavities before they are irreversibly triggered to expose the cavity content to the outside environment. Here, we report a novel micro-scale one-shot valve made of graphene transferred on to silicon-nitride (Si_xN_y) membranes. The valve triggers thermo-mechanically in 15.4±3.9 msec consuming 142.1±13.5 mW electrical power, corresponding to 2.2 mJ input energy. The valve membrane can sustain a differential pressure of 2 bars. The graphene serves multiple purposes in the device, acting as an atomically thin barrier to gas-diffusion, a resistive heater, and a source of stress in triggering the valve owing to its negative thermal expansion coefficient (TEC). The valve is designed to trigger and expose arrays of nanogram micro-packets of reactive alkali metal atoms such as rubidium, exposing it to atmospheric oxygen causing it generate heat. This heat can be used for massively parallel vaporization of vaporizable polymer electronics. A 1 mm³ Li-battery can trigger 1580 valves on a single chip for enabling transient electronics.