Electrospun Environment-Friendly Poly (L-Lactic Acid)/CO2-Based Polyurea Nanofiber Film for Piezoelectric Sensor

Developing piezoelectric polymers which have environmental-friendly raw material resources and can be used for wearable electronic devices, are of great significance for reducing dependence on fossil energy and achieving the goal of carbon neutrality. Poly (L-lactic acid) (PLLA) is a bio-based piezoelectric polymer and has important research value. To optimize the properties of materials, electrospinning technology is used for preparing nanofiber films by combining PLLA with CO2-based polyurea (PU) synthesized from CO2 and diamine, and assembling the piezoelectric sensors. The results show that when the amount of PU is 16 wt%, the voltage of the PU/PLLA piezoelectric sensor is 19 V, which is 15 times that of the PLLA piezoelectric sensor and has good stability and durability. The high dipole moment of -NH-CO-NH- in PU and the synergistic effect between PU and PLLA are the keys to improving the piezoelectric property of nanofiber film. This is the first report on the preparation of composite piezoelectric materials using CO2-based polymer and PLLA. PU/PLLA piezoelectric sensor can produce a good piezoelectric response to human vital signs and motion states. As a self-powered sensor, it has potential application in the field of intelligent wearable devices.