ABSTRACT
The idea of batteryless nanosensors is put forward. The energy for nanosensor operation can be tapped from the plentiful vibrational energy available in the environment by applying triboelectric and piezoelectric effects, where nanoscale roughness of rubbed materials and the nanowire shapes of conductors play crucial roles. Additionally, photoelectric and Seebeck effects are exploited. Principles of triboelectric and piezoelectric nanonogenerators (TENG and PENG) are explained. Both these effects are shown to originate from the second term of Maxwells’ displacement current concerned with dielectric polarization in materials. Contacting of materials and their separation in triboelectric nanogenerators and application/release of mechanical stress in piezoelectric nanogenerators are both shown to produce alternating currents. TENG-based sensors for pH, ethanol, dopamine and mercury ion as well as for static/dynamic pressure measurement are described. PENG-based sensors include pressure/speed, UV/pH and Hg2+ ion sensors, and also the smelling electronic skin. A photovoltaic-effect powered H2S nanosensor and a thermolectricity powered temperature nanosensor are discussed.
