Strain-controlled power devices as inspired by human reflex

In this work, we present a bio-inspired strain-controlled power MEMS device (SPD) based on the piezotronics effect which could directly control output power density in response to mechanical stimuli. Ultra-high values of output power density ( W/cm^2) control under a weak force (mN) control are achieved. The output power density of the SPD increases to W/cm^2 under an external strain of 16 mN, which also exhibits a good sensitivity. The strain-induced piezoelectric polarization charge can contribute to modifying the conduction band distribution at the local AlGaN/AlN/GaN heterojunction, and effectively adjust the concentration of 2DEG to tune/control the output current and power density of the SPD. In analogy to the ultimate control capability of the brain in the biological model, the gate voltage bias of the SPD can directly control the output power. This structure combines the advantages of high output power density and the programmable gate-control response of AlGaN/AlN/GaN heterojunction HEMT by using the piezoelectric effect of flexible GaN-based cantilevers.