A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Piezoelectric cantilever microphone, microspeaker, and voltage-to-frequency converter
A micromachined piezoelectric cantilever device that can be used as a microphone, a microspeaker, and a voltage-to-frequency converter, has been fabricated and tested. The 2000 x 2000 x 4.7 micron3 cantilever has a 1.3-micron-thick zinc oxide (ZnO) piezoelectric thin film on a supporting layer of low-pressure chemical-vapor-deposited (LPCVD) low-stress silicon nitride. The cantilever has no low-temperature oxide (LTO) layer over the ZnO layer, unlike our previous devices. This structural modification frees the fabrication processes from the problems brought about by the use of ZnO in integrated circuit fabrication facilities. The measured cantilever microphone sensitivity is around 3 mV/microbar in the low-frequency range which extends up to 2 kHz. The cantilever microspeaker also can be used as a voltage-to-frequency converter by the addition of a silicon top plate and an aluminum (Al) sputtered layer on the backside of the cantilever. The resonant frequency of the microspeaker is changed by the potential applied between the top plate and the backside Al layer. As the potential is changed from 0 to 40 V, the resonant frequency shifts down from 14.5 kHz to 11.5 kHz. The frequency shift of the microspeaker can be detected remotely with a microphone.
Piezoelectric cantilever microphone, microspeaker, and voltage-to-frequency converter
A micromachined piezoelectric cantilever device that can be used as a microphone, a microspeaker, and a voltage-to-frequency converter, has been fabricated and tested. The 2000 x 2000 x 4.7 micron3 cantilever has a 1.3-micron-thick zinc oxide (ZnO) piezoelectric thin film on a supporting layer of low-pressure chemical-vapor-deposited (LPCVD) low-stress silicon nitride. The cantilever has no low-temperature oxide (LTO) layer over the ZnO layer, unlike our previous devices. This structural modification frees the fabrication processes from the problems brought about by the use of ZnO in integrated circuit fabrication facilities. The measured cantilever microphone sensitivity is around 3 mV/microbar in the low-frequency range which extends up to 2 kHz. The cantilever microspeaker also can be used as a voltage-to-frequency converter by the addition of a silicon top plate and an aluminum (Al) sputtered layer on the backside of the cantilever. The resonant frequency of the microspeaker is changed by the potential applied between the top plate and the backside Al layer. As the potential is changed from 0 to 40 V, the resonant frequency shifts down from 14.5 kHz to 11.5 kHz. The frequency shift of the microspeaker can be detected remotely with a microphone.
Piezoelectric cantilever microphone, microspeaker, and voltage-to-frequency converter
Piezoelektrisches Konsolmikrophon, Mikrolautsprecher und Spannungs-Frequenz-Umsetzer
Lee, S.S. (author) / White, R.M. (author)
1995
6 Seiten, 18 Bilder, 9 Quellen
Conference paper
English
Mikrophon , Lautsprecher , Spannung (elektrisch) , Frequenzumsetzer , Piezoelektrizität , Test (Prüfung) , Zinkoxid , Dünnschicht , CVD-Beschichten , Oxidschicht , Niedrigtemperatur , integrierter Schaltkreis , Empfindlichkeit , Niederfrequenz , Resonanzfrequenz , elektrisches Potenzial , Mikrobearbeitung , Siliciumnitrid , Frequenzverschiebung
MIRCOPOROUS BLOCK FOR MICROSPEAKER AND METHOD OF PREPARING THE SAME
| European Patent Office | 2020
Modeling and analysis of a bimorph piezoelectric cantilever beam for voltage generation
| British Library Online Contents | 2007
POROUS PARTICLE FOR MICROSPEAKER AND METHOD FOR PREPARING THE SAME
| European Patent Office | 2020
| British Library Online Contents | 2008