Piezoelectric sensor

About: Piezoelectric sensor is a research topic. Over the lifetime, 7127 publications have been published within this topic receiving 115903 citations.

Peristaltic micropump system with piezoelectric actuators

Abstract: This work presents a driving system for a peristaltic micropump that is based on piezoelectric actuation. The effects of the actuation sequence on pump performance are also considered. A valveless peristaltic micropump based on piezoelectric actuation is designed and fabricated using microelectromechanical system technology. The pump has three parts––silicon, Pyrex glass and commercially available bulk PZT (lead zirconate titanate) chips. The peristaltic micropump actuated by PZT chips comprises three chambers that are in series. The driving system consists of an ATmega 8535 microprocessor, a high voltage power supply, three differential amplifiers, a phase controller, an A/D converter, a 555 oscillator and an LCD module. It is supplied via a 110 Vrms 60-Hz AC line and is programmable. The system can produce step-function signals with voltages of up to 100 Vpp and frequencies ranging from 10 Hz to 1 kHz, as the inputs for the pump. Fluid pumping with air is successfully demonstrated. Additionally, 3-, 4- and 6-phase actuation sequences for the pump are designed and used to study the effects on pump performance, as revealed by the flow rate and the displacement of a pump diaphragm. The experimental results show that the flow rate and the displacement of the diaphragm actuated by the 4-phase sequence exceed those actuated by the 3- and 6-phase sequences. A flow rate of 17.6 μl min−1 and a displacement of 2.91 μm (peak-to-peak) in 4-phase peristaltic motion are achieved at 100 Hz and 100 Vpp. The results demonstrate that the pump actuated in the 4-phase sequence is the most efficient. Consequently, the actuation sequences can affect the pump performance.

The use of complex material constants to model the dynamic response of piezoelectric materials

Abstract: This paper discusses the use of complex material constants to model the response of piezoelectric materials to alternating fields. The various material constants needed to describe the behavior of piezoelectric materials in transducers are introduced. The reasons for using complex coefficients to characterize the frequency dependent dielectric, elastic and piezoelectric response of such materials are discussed. Several interpretations of the complex coefficients are reviewed.

Measuring a parameter of a pneumatic tyre on a motor vehicle

Abstract: The device comprises a unit 7 located inside a pneumatic tyre 3 and comprising a pressure sensor eg a piezoelectric sensor and/or a temperature sensor such as a thermistor, and connected to two capacitor plates 10, 11 located on the inner side of the wheel rim 2. The plates 10, 11 form with corresponding plates 12, 13 carried by a brake caliper deivce, two capacitors which are connected in a differential coupling mode to utilization means 17. The unit 7 is fed by an integrated lithium battery and transmits its information by an F.S.K. coding. Several tyres can be monitored by multiplexing from a central processor unit.