Figure 3

Representative XPS survey spectra of (a) LTCC, (b) PEN, and (c) PCB sensor surfaces. Spectra are shown for uncleaned samples and after the cleaning method deemed most efficient for each respective sample type and are offset for clarity. An increase in intensity of signals stemming from gold core level electrons can be observed, while contaminants such as carbon (C 1s) and oxygen (O 1s) are reduced.