Open AccessPiezo-electret vibration sensors designed for acoustic-electric guitars
Author(s) -
Hidekazu Kodama,
Yoshinobu Yasuno,
Tomoya Miyata,
Kunio Hiyama,
Katsunori Suzuki,
Hiroshi Koike,
Seiichiro Lida
Publication year - 2020
Publication title -
ieee transactions on dielectrics and electrical insulation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 119
eISSN - 1558-4135
pISSN - 1070-9878
DOI - 10.1109/tdei.2020.008669
Subject(s) - fields, waves and electromagnetics , engineered materials, dielectrics and plasmas
A piezo-electret vibration sensor designed for acoustic-electric guitars is evaluated. A piezo-electret, which is a cellular polypropylene electret film, is laminated with a 150-μm-thick polyethylene terephthalate (PET) film to achieve sufficient durability for general use. Additionally, a 10-μm-thick silver electrode is printed on the top surface as a shield electrode. This electrode adds a mass of only 63 mg to the sensor. The sensor is attached to the soundboard of a guitar body. An impact force is applied to the top of the saddle of the guitar body. The output voltage of the sensor owing to the vibration of the soundboard is measured by a voltage follower and an FFT analyzer. Conventional sensors that use lead zirconate titanate (PZT) ceramics are also tested. The results show that only the piezo-electret sensor detects the vibration of the soundboard over a wide frequency range up to 10 kHz. The time response of the sensor also corresponds to the vibration of the soundboard. However, the output voltage of the sensor is 1/10 to 1/100 of that of the PZT sensors. The effective d33 value of the sensor is 1.58 pC/N at 1 kHz. The value is only 1/280 of the apparent d33 value of the piezo-electret, owing to an increase in the effective elastic modulus in the thickness direction caused by lamination with the PET film.