Postdoctoral fellow Anyin Li demonstrates the use of a sliding triboelectric nanogenerator to produce electrical charges for the mass spectrometer shown next to him. Photo: Rob Felt.
By John Toon
Triboelectric nanogenerators (TENG) convert mechanical energy harvested from the environment into electricity for powering small devices such as sensors. Now, researchers have harnessed this technology to dramatically boost the sensitivity of mass spectrometers, instruments that identify molecules by their mass.
Beyond boosting sensitivity, replacing conventional power supplies with TENG devices allows identification to be done with smaller samples, conserving precious biomolecules or chemical mixtures that may be available only in minute quantities. Georgia Tech researchers believe the unique aspects of the TENG output — oscillating high voltage and controlled current — improve the ionization process, increasing the voltage applied without damaging samples or the instrument.
A contact-separation triboelectric nanogenerator produces electrical charge when surfaces are brought together and then separated.
“Our discovery is basically a new and very controlled way of putting charge onto molecules,” said Facundo Fernández, a professor in Georgia Tech’s School of Chemistry and Biochemistry. “We know exactly how much charge we produce using these nanogenerators, allowing us to reach sensitivity levels that are unheard of — at the zeptomole scale. We can measure down to literally hundreds of molecules without tagging.”
“The total charge delivered in each cycle is entirely controlled and constant regardless of the speed at which the TENG is triggered,” Wang said. “This is a new direction for the triboelectric nanogenerators and opens a door for using the technology in the design of future instrumentation and equipment.”
The research, which was supported by the National Science Foundation, NASA Astrobiology Program, and the Department of Energy, was reported in the journal Nature Nanotechnology.