A Glass-Based Paraffin Micro Actuator Array for Ultra-Low Flowrate Micropump

This paper presents compact micro actuators that achieve large output force and stroke utilizing paraffin as phase change material (PCM) activated via joule heat. A glass chamber, sealed with a double-layered composite diaphragm, constrains the deflection induced by phase change in the out-of-plane direction. Each individual actuator has a volume of less than <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$1\ \text{mm}^{3}$</tex>. Devices with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$700\ \mu \mathrm{m}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$300\ \mu \mathrm{m}$</tex> chamber depths achieved maximum deflection of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$233.51\ \mu \mathrm{m}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$90.27\ \mu \mathrm{m}$</tex>, and work density up to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$26.08\times 10^{3}\mathrm{J}/\mathrm{m}^{3}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3.50\times 10^{3}\mathrm{J}/\mathrm{m}^{3}$</tex>, respectively. A 3-actuator array <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(5\ \text{mm}\times 2\text{mm}\times 1\ \text{mm})$</tex> was integrated with a microchannel to form a micropump, delivering ultra-low flowrate of 4–6 nL/min.