A correct ultraviolet light (UV) exposure is critical not only for successful photolithographic pattern definition but also for subsequent SU-8 chemical removal. Gaudet et al. have determined the critical exposure dose threshold for polymerization to be 49.4 mJ cm -2 . This dose needs to be adjusted for thickness to ensure that buried layers are exposed above the threshold. This can be done using the absorption coefficient at 365 nm wavelength determined by Gaudet et al., which initially is 38 cm -1 and increases up to 49 cm -1 after very high exposures (415 mJ cm -2 ). As an approximation, we have assumed the absorption coefficient to be 43 cm -1 . It is important to emphasize here the need to filter short wavelength radiation (< 365 nm) when using non-monochromatic light sources, as severely overexposed surface layers are obtained otherwise. This leads to fabrication defects and more difficult SU-8 removal. Interference standing waves due to the light reflection in the substrate can lead to inhomogenous photoresist exposure, requiring a higher UV dose and leading to difficulties in SU-8 removal. Other than the choice of metallization, no special precautions were taken in our experiments to reduce UV reflection (45% for the chosen Pt/Ti metallization). We have tested the here described chemical removal protocol on three different SU-8 formulations by Micro Resist Technology GmbH: SU-8 2002, SU-8 2005, and SU-8 2150. SU-8 was spin coated at 4000 rpm for 40 s with a 10 s ramp up time. A soft pre-bake of the coating was done by ramping the temperature up for 10 min, sustaining 95 • C for 2 min (30 min for thickness > 100 µm), and then ramping down for 20 min. After UV exposure at a dose adequate for the desired film thickness, a post exposure bake was done at 70 • C for 2 min, then 95 • C for another 2 min (12 min for thickness > 100 µm) and then ramping down for 20 min. The conditions used for SU-8 polmerization are summarized in Table .