Surface roughness measurement using a polymer-based capacity micromachined ultrasonic transducer

Abstract

In this paper, the polymer-based capacitive micromachined ultrasonic
transducer (CMUT) is developed for measuring the surface roughness of
materials. The transducer is designed to evaluate surface roughness with
five modes: full transmission/ full reception, majority transmission/ majority
reception, majority transmission/ minority reception, minority transmission/
majority reception, minority transmission/ minority reception. Experiments
indicate that the full transmission/ full reception mode has the greatest
signal output and the minority transmission/ majority reception mode can
obtain good signal with better energy efficiency. The result shows the
CMUT can identify the surface roughness of sandpaper with surface
roughness Rrms ranging from 11.4μm to 179.8μm.