Sensors 2008. 8 2322 frequency-based measurement including wireless implementations. The high resistance at the contact was believed to be due to the protective oxide layer of stainless steel. One simple method to circumvent this is to rougher faces of the steel using various physical methods such as lapping and grit blasting to remove the oxide layer. The devices used for the wireless tests were constructed with top (50-Hm thick) and base (100-um thick) plates whose outer surfaces were mechanically roughened prior to bonding of the copper coils. The bonding was performed using a silver-filled conductive adhesive with low-resistivity(<2x10.cm), improving the electrical connection between Figure 3. Fabrication process flow to fabricate the capacitive pressure sensor(steps I 4)and the L-C tank(step 5) Stainless steel i Stainless steel B A B Define base plate by EDM Cut out top plate by EDM 2 A Apply liquid polyurethane Place top plate (self-aligned) Release device Conductive epoxy Wind insulated wire bond both terminalsSensors 2008, 8 2322 frequency-based measurement including wireless implementations. The high resistance at the contact was believed to be due to the protective oxide layer of stainless steel. One simple method to circumvent this is to roughen the surfaces of the steel using various physical methods such as lapping and grit blasting to remove the oxide layer. The devices used for the wireless tests were constructed with top (50-μm thick) and base (100-μm thick) plates whose outer surfaces were mechanically roughened prior to bonding of the copper coils. The bonding was performed using a silver-filled conductive adhesive with low-resistivity (<2×10-4 Ω⋅cm), improving the electrical connection between them. Figure 3. Fabrication process flow to fabricate the capacitive pressure sensor (steps 1- 4) and the L-C tank (step 5)