1. In situ fabrication of porous polymer films embedded with perovskite nanocrystals for flexible superhydrophobic piezoresistive sensors.
- Author
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Xuan, Wufan, Fang, Yuan, Teng, Shuhua, Huang, Sheng, Zou, Liang, Gao, ShaSha, Cheng, Yongchao, and Zheng, Lina
- Subjects
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POROUS polymers , *POLYMER films , *PEROVSKITE , *PRESSURE sensors , *RANDOM forest algorithms , *DETECTORS - Abstract
[Display omitted] • A flexible pressure sensor was constructed with MAPbBr 3 in the matrix of PVDF. • A porous polymer composite with superhydrophobicity was synthesized in situ. • The mechanism of the sensor's response is explained by the DFT and MEPs. • The sensor can monitor human physiological signals and wind speed very well. • Feature engineering and machine learning improved detection accuracy in 60 tests. The application of pressure sensors based on perovskite in high-humidity environments is limited by the effect of water on their stability. Endowing sensors with superhydrophobicity is an effective strategy to overcome the issue. In this work, MAPbBr 3 /Polyvinylidene Fluoride-TFSI composite was prepared by a one-step in-situ strategy to form a flexible superhydrophobic pressure sensor, which exhibited a contact angle of 150.25°. The obtained sensor exhibited a sensitivity of 0.916 in 1 kPa, a detection limit of 0.2 Pa, a precision of 0.1 Pa, and a response/recovery of ∼100 ms, along with good thermal stability. Through density functional theory calculations, it is revealed that the formation of the porosity is attributed to the interaction between the polymer and EMIM TFSI, which further leads to superhydrophobicity. And, the perovskite structure is easy to change under pressure, affecting the carrier transport and electrical signals output, which explains the sensing mechanism. In addition, the sensor performed well in monitoring facial expression, pulse, respiration, finger bending, and wind speed ranging from 1 m/s to 6 m/s. With both the Linear Regression and the Random Forest algorithm, the sensor can monitor the wind speed with an R2 greater than 0.977 in 60 tests. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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