Apparatus and method for preparing microparticles using in-line solvent extraction. The TPU includes safety equipment, a safety TPU-part having a first communication unit and a main TPU-part having a third communication unit. The method further includes attaching the hair strands to the clip such that the clip is substantially concealed by the strands when the clip is attached to the user’s natural hair. The deposited layers are patterned and etched, a spacer layer is formed over sidewalls of the capacitor to prevent capacitor sidewall leakage.