An apparatus for sensing a target substance includes a substrate, an elongated electroactive cantilever, a functional layer and an electrical sensor. The photoresist composition includes a photoacid generator having an onium salt and an i-line reactive sensitizer. Alteration of video quality of the set of video frames includes altering a frame rate, altering a pixel resolution, andor altering color resolution of the set of video frames andor altering a ratio of independent frames to predictive frames of the set of frames.