Department of Materials Science and Engineering, Korea University, 145, Anam-ro Seongbuk-gu Seoul, 02841, Republic of Korea.
School of Electrical Engineering, Korea University, 145, Anam-ro Seongbuk-gu Seoul, 02841, Republic of Korea.
Nanoscale. 2023 May 4;15(17):7980-7990. doi: 10.1039/d2nr05688g.
In this study, a temperature-insensitive strain sensor that detects only the strain without responding to the temperature was designed. The transport mechanism and associated temperature coefficient of resistance (TCR) of a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) thin film were modified through secondary doping with dimethyl sulfoxide (DMSO). Upon DMSO-doping, the carrier transport mechanism of the PEDOT:PSS thin film transitioned from hopping to band-like transport, with a morphological change. At the DMSO doping level, which caused the critical point of the transport transition, the resistance of the thin film was maintained with a change in temperature. Consequently, the TCR of the optimized PEDOT:PSS thin film was less than 9 × 10 K, which is 10 times lower than that of the as-prepared films. The carrier mobility of the PEDOT:PSS thin film was effectively improved with the morphological change due to DMSO doping and was investigated through combinational analysis. Ultimately, the wearable strain sensor prepared using the optimized PEDOT:PSS thin film responded stably to the applied strain with a gauge factor of 2 and exhibited excellent temperature anti-interference.
在这项研究中，设计了一种仅对应变敏感而不对温度响应的温度不敏感应变传感器。通过用二甲基亚砜（DMSO）进行二次掺杂，改变了聚（3,4-乙二氧基噻吩）：聚（苯乙烯磺酸盐）（PEDOT：PSS）薄膜的传输机制和相关的电阻温度系数（TCR）。在 DMSO 掺杂后，PEDOT：PSS 薄膜的载流子输运机制从跳跃输运转变为能带输运，并发生了形态变化。在导致输运转变临界点的 DMSO 掺杂水平下，薄膜的电阻随温度变化而保持不变。因此，优化后的 PEDOT：PSS 薄膜的 TCR 小于 9×10 K，比原始薄膜低 10 倍。通过 DMSO 掺杂引起的形态变化，有效地提高了 PEDOT：PSS 薄膜的载流子迁移率，并通过组合分析进行了研究。最终，使用优化后的 PEDOT：PSS 薄膜制备的可穿戴应变传感器对施加的应变稳定响应，其应变系数为 2，表现出优异的温度抗干扰能力。
