Sang Shengbo

Piezoresistive properties of resonant tunneling diodes

A measurement system was designed and established to test the piezoresistive properties of resonant tunneling diodes (RTDs). The current-voltage characteristic shifts of RTD at different stress states were detected. The experimental results demonstrate that the piezoresistive sensitivity of RTD is larger than 1 × 10−8 Pa−1. To accurately represent the piezoresistive properties of RTD, the current-voltage characteristic coherence of the same RTD was tested. According to the experimental results, the largest relative resistance shift of an RTD in the same measurement environment is less than 3%, of which 1% is caused by the testing apparatuses.

Highly sensitive wearable strain sensor based on silver nanowires and nanoparticles

Here, we propose a highly sensitive and stretchable strain sensor based on silver nanoparticles and nanowires (Ag NPs and NWs), advancing the rapid development of electronic skin. To improve the sensitivity of strain sensors based on silver nanowires (Ag NWs), Ag NPs and NWs were added to polydimethylsiloxane (PDMS) as an aid filler. Silver nanoparticles (Ag NPs) increase the conductive paths for electrons, leading to the low resistance of the resulting sensor (14.9 Ω). The strain sensor based on Ag NPs and NWs showed strong piezoresistivity with a tunable gauge factor (GF) at 3766, and a change in resistance as the strain linearly increased from 0% to 28.1%. The high GF demonstrates the irreplaceable role of Ag NPs in the sensor. Moreover, the applicability of our high-performance strain sensor has been demonstrated by its ability to sense movements caused by human talking, finger bending, wrist raising and walking.