A micro-machined hydrophone employing a piezoelectric body combined on the gate of a field-effect transistor

EGFET-Based Sensors for Bioanalytical Applications: A Review

“…Therefore, the increase of W impacts the performance, especially for low-frequency applications [ 14 ]. In addition to the flicker noise, both the device and the transduction interface are intrinsically affected by thermal noise, depending on the leakage current at the oxide interface [ 14 , 15 ]. Thermal noise spectral density has been investigated in MOSFETs by Van der Spiegel in strong, moderate, and weak inversion regions in high- W / L devices.…”

“…The main applications of EGFETs are associated with the detection of ionic species, pH, and specific molecules (through the functionalization of sensitive surfaces) such as urea and glucose [ 7 , 8 , 9 , 10 , 11 , 12 ]. Apart from its prevalent use in the fields of biosensing and chemical sensing, physical sensors for high-frequency ultrasound detection (e.g., hydrophones) have been realized through EGFET technology, often referred to as piezoelectric-oxide-semiconductor field-effect transistors (POSFETs) or piezoelectric gate on FETs (PiGoFETs) [ 13 , 14 , 15 ].…”

Design and simulation of a flat cap mushroom shape microelectromechanical systems piezoelectric transducer with the application as hydrophone

“…Moreover, the miniaturisation of hydrophones is very attractive for developers [17][18][19]. Thanks to the microelectromechanical systems (MEMS) technology, traditional underwater systems are replaced with micro-scale transducers with the same or better performances.…”

“…In [29], a hydrophone is fabricated by using PVDF on the extended gate electrode of an MOSFET. Recently, diaphragms have been used as acoustic pressure amplifiers on top of the piezoelectric materials on the gates of the transistors [17,18].…”

Fabrication and Characterization of High-Sensitivity Underwater Acoustic Multimedia Communication Devices with Thick Composite PZT Films

“…The applications of hydrophones have been restricted by the sensitivity, desired resonance frequency, and device shape. Hydrophone miniaturization has been a subject of study in recent years [1][2][3]. However, miniaturization of most conventional acoustic transducers is limited to low resolution, less sensitivity, and high impedance at low frequencies and the performance curve is no longer understandable [4] Micromachined ultrasonic transducers which integrate piezoelectric layers on silicon substrate offer an excellent solution to overcoming the shortcomings of conventional acoustic transducers [5][6][7].…”