Development of various designs of low-power, MEMS valves for fluidic applications

A Parylene MEMS Electrothermal Valve

“…When higher currents were applied to compensate for the increased heat loss to the fluid, premature failure of the Pt element was observed before complete valve opening. The current overshoot provided by the power supply was less than 1%, so trace failure may be attributed to other causes such as thermal stress induced by the difference of the coefficients of thermal expansion between Pt and Parylene (e.g., Pt of 9.1 × 10 −6 /°C versus Parylene of 3.5 × 10 −5 /°C) or electromigration (the atoms in the Pt trace are removed due to the impact with high-energy electrons) [5], [10]. Therefore, current ramping was applied to optimize the heat transfer to the Parylene membrane for operation in water/liquid.…”

Novel enhancement of thin-form-factor galvanic cells: Probing halogenated organic oxidizers and metal anodes

“…Also, mechanical micro valves and vents are currently being developed for the development of automated batteries [45,46].…”

A Wirelessly–activated Parylene Electrothermal Valve for Mapping Brain Function in Freely Moving Subjects

“…Normally-closed MEMS electrothermal valves capable of rapid opening provide a potential solution for the new MIP system. Previously, electrothermal valves have been developed but only one of these is suited for implantable drug delivery (Table 1) [3][4][5][6][7][8]. This valve consists of a resistive metallic membrane (Pt/Ti/Pt) suspended over a drug reservoir that opens when an applied current melts the membrane.…”