Sub-Hz self-powered sensing based on mechanical-buckling driven hot-electron injection

Physical processes like changes in ambient temperature, pressure, material accumulation or growth induce stress/strain responses in structures (civil or biomechanical) that occur at frequencies ranging from Hz down to micro-Hertz (μHz). The quasi-static nature of this process poses a challenge for designing self-powered sensors that not only monitor these physical processes but at the same time scavenge operational energy for sensing, computation and storage from the signal being monitored. In this paper we propose a novel sub-Hz self-powered sensing approach which exploits the combination of the physics of post-buckling response in slender elastic columns and the physics of hot-electron injection in floating-gate transistors. Experimental results using a fabricated prototype demonstrate that the sensor can self-power, compute and record the statistics of quasi-static input signals operating at frequencies down to 1mHz.