Design and Optimization of High-Performance Through Hole Based MEMS Energy Harvester Using PiezoMUMPs

Piezoelectric energy harvesting is an emerging area of research to meet the demand of nonconventional energy sources. In this paper, we have designed and analysed high-performance micro-electromechanical system (MEMS) piezoelectric energy harvesters by incorporating a through-hole in the classical cantilever configuration. The harvesters are designed using piezoelectric multi-user MEMS processes (PiezoMUMPs), where aluminum nitride (AlN) piezoelectric material is chosen on silicon substrate. A unique optimization method is applied to deduce a critical ratio of hole length to cantilever length as 0.2–0.26 for structures that are not tip mass-based and 0.4–0.5 for tip mass-based structures to achieve maximum power harvesting capability. The performance of the proposed harvesters is observed to be superior in comparison to that reported in the literature in terms of improved voltage and power harvesting capability and less area requirement. The classical cantilever topology with unoptimized and optimized holes produces power of 423 nW with normalized power density (NPD) of 12.78 μW/mm3/g2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{3}/\hbox {g}^{2}$$\end{document} and 490 nW with NPD of 14.95μW/mm3/g2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$14.95 \mu \hbox {W}/\hbox {mm}^{3}/\hbox {g}^{2}$$\end{document}, respectively, at load resistance of 1MΩ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1 \hbox { M}\Omega $$\end{document} with application of 1 g acceleration. Furthermore, a comprehensive analysis of PiezoMUMPs design guidelines for designing hole-based harvesters is presented, and a layout of the harvesters to be fabricated is also provided.