(Invited) Self-Powered Heavy Metal Sensors Based on Triboelectric and Thermoelectric Effects

Self-powered sensors have shown their superior advantages and become more popular when comparing to other traditional sensing technologies. In the past years, we have developed self-powered sensors based on triboelectric and thermoelectric effects for the detection of metal ions and small molecules. In those self-powered sensors, functional nanomaterials will act as core materials to spontaneously generate electric outputs by environmental mechanical motions or temperature differences as well as recognition elements for highly specific reaction with mercury ions. For example, those self-powered sensors can provide a high sensitivity (LOD of 1.7 nM) and good linear range (from 10 nM to 1 mM) toward mercury ion detection. The selectivity of those self-powered sensors is also evaluated. Among the investigated metal ions, only Hg 2+ ions result in a distinct output voltage change, by approximately 9 times. Those self-powered sensors exhibit the capability to clearly distinguish even a small concentration of Hg 2+ ions from the presence of various other species in environmental samples. With the simplicity (no complex circuitry or power supply involved) and low-cost fabrication mechanism (small-sized; minimal and low-priced materials required), those self-powered sensors demonstrate great potential to serve as new prototypes of portable devices for the in-field sensing of samples