REU Students Demonstrate the Viability of Energy Harvesting for Self-Powered Sensors

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Students in the Research Experiences for Undergraduates (REU) program at the Center for Compact and Efficient Fluid Power (CCEFP), an NSF-funded Engineering Research Center (ERC) headquartered at the University of Minnesota, have set several new benchmarks for the use of Hydraulic Pressure-Ripple Energy Harvesting (HPEH) for self-powered sensors. The students designed and tested a total of nine viable prototype devices, representing six distinct generations of designs that will significantly advance both power generation performance and power density.


The HPEH prototypes were developed with a flexible design that used combinations of commercially available piezoelectric elements to permit easier device configurations at different target power demands. The portfolio of inventions ultimately enables the viability of HPEH-powered devices across a broad range of power demands, available energy densities, form factors, static pressures, and target applications.


Several of the prototypes developed by the CCEFP students advanced the potential of HPEH applications: Advancement in the energy harvesting circuit with inductance matched to the piezoelectric energy conversion element within an HPEH yielded a prototype with peak power output of 3.3 milliwatts (mW). Another prototype was developed for compact, low-power sensing applications and achieved its required target output of 67 microwatts (µW). The first HPEH-powered, wireless temperature sensor was demonstrated. And a single-crystal piezoelectric variant HPEH prototype yielded twice the power density compared to variants using co-fired multi-layer piezoelectric elements.