Wireless Measurement of the Degradation Rates of Thin Film Bioresorbable Metals Using Reflected Impedance

—A method using reflected impedance to determine the electrical degradation rates of bioresorbable metals for physically transient electronic devices is outlined. This approach uses known mutual inductor interactions with simple single turn disk coil geometries and a frequency measurement system to track the reduction of the mean thickness of a thin film metal ring as it degrades. Experiments using 500nm thick zinc rings, fabricated by photolithography, thermal evaporation and lift-off, found a mean degradation rate of 278nmh −1 in 37°C de-ionised water. Experiments in 37°C 1 mM hydrochloric acid found two distinct periods of degradation and a total degradation rate of 632nmh −1 that closely matched the degradation rate measured using profilometry of 608nmh −1 . into mm sections using a 390 fs pulse duration and 100 µJ pulse using to the beam at with a 2 ◦ angle of attack. Scan speed 15 mm s −1 with a pulse frequency of 100 kHz. Cut lines were repeated 10 times for each square. This setup allowed for dicing of the silicon wafer with minimal edge defects, without additional degradation the