Feasibility of Top-Orthogonal-to-Bottom Electrode (TOBE) 2D CMUT arrays for low-channel-count 3D imaging

Capacitive micromachined ultrasound transducers (CMUTs) offer many potential advantages over piezoelectric transducers, and hold promise for cost-effective 2D arrays. Fully-wired 2D arrays are cost-prohibitive due to large channel counts. We present what we call Top-Orthogonal-to-Bottom Electrode (TOBE) 2D CMUT arrays with the potential to perform 3D imaging with an N×N 2D array using only N transmit channels and N receive channels. Candidate fabrication technologies are discussed and a modified sacrificial release process is used to fabricate a prototype. Performance of two imaging schemes is discussed.