Mechanical energy scavengers convert irregular input mechanical energy into irregular electrical output. There is a need to enable uniform and predictable electric output from energy scavengers regardless of the variability in the mechanical input. So, in this work, a mechanical frequency regulator is proposed that fixes the input forces and input frequency acting on a triboelectric nanogenerator, thus enabling predictable electric output. The irregular low frequency mechanical input energy is first stored in a spiral spring following which the energy is released at the desired frequency by means of an appropriate design of gear train, cam, and flywheel. By regulating the nanogenerator output at 50 Hz, a standard power transformer can be optimally driven to increase the output current to 6.5 mA and reduce its voltage to 17 V. This output is highly compatible for powering wireless node sensors as is demonstrated in this work.
Bibliographical noteFunding Information:
grounded electrode-type TENG schematic is shown in Figure S1 in the Supporting Information. The substrates were 3D printed using polylactic acid (PLA). Aluminum foil of thickness 70 µm was used as electrodes and was attached to the PLA substrates using commercial double-sided tape (polyethylene foam). Polytetrafluoroethylene (PTFE) film of 80 µm thickness was used as the top dielectric (negative dielectric). Ionic thermoplastic polyurethane (TPU) of thickness 200 µm was used as the bottom dielectric (positive dielectric).[29,30] Effective contact area was 5 × 5 cm2. Four spacer springs each of stiffness 160 N m−1 separated PTFE and TPU. Four bumper springs each of stiffness 400 N m−1 were used to enhance the TENG output as well as serve as separator between middle layer and bottom layer of the Gnd-TENG.[28,31] The springs were supported by the PLA substrate and made no contact with the dielectric and electrode materials.
This research was financially supported by the Samsung Research Funding Center of Samsung Electronics under Project number SRFC-TA1403-51, and by a grant from the Kyung Hee University in 2015 (KHU-20150653).
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)