Middle Ear Ossicular Chain Vibration Detection by Means of an Optimized MEMS Piezoelectric Accelerometer

Microelectromechanical (MEMS) piezoelectric accelerometers are diversely used in consumer electronics and handheld devices due to their low power consumption as well as simple reading circuit and good dynamic performance. In this paper, a tri-axial piezoelectric accelerometer with folded beams is presented. The four beam suspensions are located at two sides of the mass aligned with edges of the mass, and the thickness of the beams is the same as the thickness of the mass block. In order to realize the multi-axis detection, a total of 16 sensing elements are distributed at the end of the folded beams. The structural deformations, stress distribution, and output characteristics due to the acceleration in x-, y-, and z-axis directions are theoretically analyzed and simulated. The proposed accelerometer is fabricated by MEMS processes to form Mo/AlN/ScAlN/Mo piezoelectric stacks as the sensing layer. Experiments show that the charge sensitivity along the x-, y-, and z-axes could reach up to ~1.07 pC/g, ~0.66 pC/g, and ~3.35 pC/g. The new structure can provide inspiration for the design of tri-axial piezoelectric accelerometers with great sensitivity and linearity.

Section: Introductionmentioning

confidence: 99%

A Novel Tri-Axial Piezoelectric MEMS Accelerometer with Folded Beams

Liu

Cai

et al. 2021

“…Various types of middle-ear implant transducers [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ] that stimulate round window (RW) have been developed [ 11 , 12 , 13 , 14 , 15 ]. However, there is no highly stable and practical RW transducer for middle-ear implants except for the floating mass transducer (FMT) developed by MED-EL Inc. (Innsbruck, Austria) [ 16 , 17 ].…”

Section: Introductionmentioning

confidence: 99%

Design Study of a Round Window Piezoelectric Transducer for Active Middle Ear Implants

Shin

2021

This report describes the design of a new piezoelectric transducer for round window (RW)-driven middle ear implants. The transducer consists of a piezoelectric element, gold-coated copper bellows, silicone elastomer (polydimethylsiloxane, PDMS), metal cylinder (tungsten), and titanium housing. The piezoelectric element is fixed to the titanium housing and mechanical resonance is generated by the interaction of the bellows, PDMS, and tungsten cylinder. The dimensions of PDMS and the tungsten cylinder with output characteristics suitable for compensation of sensorineural hearing loss were derived by mechanical vibrational analysis (equivalent mechanical model and finite element analysis (FEA)). Based on the results of FEA, the RW piezoelectric transducer was implemented, and bench tests were performed under no-load conditions to confirm the output characteristics. The transducer generates an average displacement of 219.6 nm in the flat band (0.1–1 kHz); the resonance frequency is 2.3 kHz. To evaluate the output characteristics, the response was compared to that of an earlier transducer. When driven by the same voltage (6 Vp), the flat band displacement averaged 30 nm larger than that of the other transducer, and no anti-resonance was noted. Therefore, we expect that the new transducer can serve as an output device for hearing aids, and that it will improve speech recognition and treat high-frequency sensorineural hearing loss more effectively.

“…Micro-electro-mechanical system (MEMS) acceleration sensors, with the advantages of low cost, low power consumption, high compatibility with integrated circuit (IC) process and high integration [ 1 , 2 , 3 , 4 ], have a wide range of applications in automotive electronics, structural health monitoring, navigation and other fields [ 5 , 6 , 7 , 8 ]. MEMS acceleration sensors usually include piezoresistive [ 9 , 10 ], capacitive [ 11 ] and piezoelectric acceleration sensors [ 12 , 13 ].…”

Section: Introductionmentioning

confidence: 99%

Characteristics Research of a High Sensitivity Piezoelectric MOSFET Acceleration Sensor

Zhao

2020

In order to improve the output sensitivity of the piezoelectric acceleration sensor, this paper proposed a high sensitivity acceleration sensor based on a piezoelectric metal oxide semiconductor field effect transistor (MOSFET). It is constituted by a piezoelectric beam and an N-channel depletion MOSFET. A silicon cantilever beam with Pt/ZnO/Pt/Ti multilayer structure is used as a piezoelectric beam. Based on the piezoelectric effect, the piezoelectric beam generates charges when it is subjected to acceleration. Due to the large input impedance of the MOSFET, the charge generated by the piezoelectric beam can be used as a gate control signal to achieve the purpose of converting the output charge of the piezoelectric beam into current. The test results show that when the external excitation acceleration increases from 0.2 g to 1.5 g with an increment of 0.1 g, the peak-to-peak value of the output voltage of the proposed sensors increases from 0.327 V to 2.774 V at a frequency of 1075 Hz. The voltage sensitivity of the piezoelectric beam is 0.85 V/g and that of the proposed acceleration sensor was 2.05 V/g, which is 2.41 times higher than the piezoelectric beam. The proposed sensor can effectively improve the voltage output sensitivity and can be used in the field of structural health monitoring.