Strongly (001) Oriented Bimorph PZT Film on Metal Foils Grown by rf-Sputtering for Wrist-Worn Piezoelectric Energy Harvesters

Hong Goo Yeo, Tiancheng Xue, Shad Roundy, Xiaokun Ma, Christopher Rahn, Susan Trolier-McKinstry

Research output: Contribution to journalArticle

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For piezoelectric energy harvesters, a large volume of piezoelectric material with a high figure of merit is essential to obtain a higher power density. The work describes the growth of highly (001) oriented sputtered lead zirconate titanate (PZT) films (f ≈ 0.99) exceeding 4 µm in thickness on both sides of an Ni foil to produce a bimorph structure. These films are incorporated in novel wrist-worn energy harvesters (<16 cm2) in which piezoelectric beams are plucked magnetically using an eccentric rotor with embedded magnets to implement frequency up-conversion. The resulting devices successfully convert low-frequency vibration sources (i.e., from walking, rotating the wrist, and jogging) to higher frequency vibrations of the PZT beams (100–200 Hz). Measured at resonance, six beams producing an output of 1.2 mW is achieved at 0.15 G acceleration. For magnetic plucking of a wrist-worn nonresonant device, 40–50 µW is produced during mild activity.

Original languageEnglish (US)
Article number1801327
JournalAdvanced Functional Materials
Issue number36
StatePublished - Sep 5 2018


All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

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