| 摘要 |
A micropump for bidirectional fluid flow consists of two active diaphragm valves and a diaphragm pumping chamber, driven by unimorph piezoelectric actuators. The manufacture of the micropump comprises the following steps: A 0.3 mu m oxide film is formed on the the silicon substrate (1). Part of the oxide film is etched away by hydrogen fluoride (HF). On the remaining part of the film, a wet etching step with tetra methyl ammonium hydroxide (TMAH) is performed. After stripping the remainders of the oxide with HF a new oxide layer (1.2 mu m) is applied. The diaphragms are etched with a potassium hydride (KH) solution, thereby determining the thickness of the diaphragm. Then a glass substrate (2) having laser-cut through-holes (o 0.6 mm) is bonded to the silicon substrate. The packings of the valve diaphragms are clamped between glass and silicon substrates by anodic bonding. Finally the piezoelectric actuators are attached to valve and pumping diaphragms. The thickness of packing and/or diaphragm can be adjusted to determine the valve strength. Additional layers (9) preventing adhesion can be coated on the glass substrate surface, thereby realising packings with higher fluid tightness. <IMAGE> |
