May 16, 2014
Managing power in triboelectric nanogenerators for wireless sensing
The triboelectric effect is one of a few effects that have been known for thousands of years. Triboelectric nanogenerators (TENGs) are a new and powerful approach for energy harvesting. Nevertheless, the output of a TENG has the common characteristics of a high voltage but low current and total transported charges. Therefore, it needs transformation before being applied to drive conventional electronics. Reported here in Nanotechnology are the first steps towards this.
The schematic of the power-transformed-and-managed triboelectric nanogenerator and its wireless sensing application
The power transformation of a TENG involves the lowering of the output voltage, while increasing the output charges and current. This is different from the traditional method of using a transformer for a sinusoidal-type AC signal because the output of a TENG can be a short pulse at variable frequency.
Power transformation and management
A research group led by Zhong Lin Wang with members including Wei Tang and colleagues at the Beijing Institute of Nanoenergy and Nanosystems in Chinese Academy of Sciences have developed a power-transformed-and-managed TENG (PTM-TENG). They integrate a contact-separation-mode TENG with a self-connection-switching capacitor array. These are connected in serial when being charged and then in parallel during discharging.
By using an eight-capacitor array, the PTM-TENG’s output charges are enhanced by eight times. In addition, the PTM-TENG’s charging/discharging mode is changed from continuous to instantaneous, which can hugely enhance the instantaneous output current and power. Furthermore, the PTM-TENG is successfully applied in a wireless touch sensor. Without any power supply, this sensor will not only detect the touch stimulation, but also convert the mechanical energy caused by the stimulation into electric power for infrared communication.
More information about the research can be found in the journal Nanotechnology 25 225402 (IOPselect article).
Thermoelectric nanodevices: Catering for global energy needs little by little (Apr 2014)
Going beyond the traditional electromagnetic generator (Mar 2014)
Flexible TEG breaks new power record (Dec 2013)
Piezophototronics makes highly sensitive skin-like sensor (Aug 2013)
About the author
Zhong Lin (ZL) Wang is the Hightower Chair in Materials Science and Engineering, Regents' Professor at Georgia Tech, Director and Principal Investigator of the Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Science. His discovery and breakthroughs in developing nanogenerators established the principle and technological roadmap for harvesting mechanical energy from environment and biological systems for powering personal electronics.