1成果简介
多功能可拉伸应变传感器在生理监测领域备受青睐，因其能够适应复杂的变形条件。然而，对于多功能可拉伸传感器而言，同时实现高可拉伸性、优异灵敏度和卓越稳定性仍是一大挑战。本文，香港中文大学（深圳）郑庆彬 助理教授在《Chemical Engineering Journal》期刊发表名为“Vertical graphene/carbon nanotube/ polydimethylsiloxane composite films for multifunctional stretchable strain sensors”的论文，研究受大象鼻子的启发，采用等离子体增强化学气相沉积（PECVD）方法，基于垂直石墨烯（VG）/碳纳米管（CNT）/聚二甲基硅氧烷（PDMS）复合薄膜开发了多功能应变传感器。
得益于VG和CNT产生的广泛褶皱、折叠和桥接微结构，以及PDMS的协同作用，所得VG/CNT/PDMS复合薄膜展现出卓越的应变传感性能，包括宽广的传感范围（拉伸性可达~100%）、高灵敏度（量程因子可达1332.5）、 优异的线性度（R^2 = 0.98）、快速响应（29 ms）、超低检测限（0.1%）以及卓越的稳定性（经过1000次应变释放循环后性能无显著衰减）。除应变传感外，VG/CNT/PDMS复合薄膜还展现出卓越的多功能特性，包括疏水表面（接触角为108°）和优异的焦耳加热能力（在15V电压下2分钟内可达到110.4°C）。VG/CNT/PDMS复合薄膜可用于空气和水下环境中的人体运动监测及开关控制，展现了其作为多功能可穿戴传感器的潜力。本研究强调了多功能可拉伸VG/CNT/PDMS复合薄膜在监测复杂运动方面的有效性，为不同环境条件下的多样化应用提供了有前景的解决方案。
2图文导读
图1. (a) Schematic diagrams of the structure of elephant trunk skin and VG/CNT/PDMS strain sensor. (b) Schematic illustration of the fabrication process for the VG/CNT/PDMS strain sensors.
图2. Characterizations of the VG and VG/CNT hybrid films. SEM images of (a) VG and (b) VG/CNT hybrid films. TEM images of (c-d) VG and (e-f) VG/CNT hybrid films. (g) Raman spectra of VG and VG/CNT hybrid films. High-resolution C1s XPS spectra of (h) VG and (i) VG/CNT hybrid films.
图3. Strain sensing performance of the VG/PDMS and VG/CNT/PDMS composite strain sensors. Relative resistance changes of (a) VG/PDMS strain sensor and (b) VG/CNT/PDMS strain sensor. (c) Relative resistance change of VG/CNT/PDMS strain sensor at tensile speeds 10, 20, 30, 40, and 50mm/min under 10% strain. (d) The response time of the VG/CNT/PDMS strain sensor at a tensile speed of 50mm/min. Cyclic durability test of 1000cycles under 10% tensile strain for (e) VG/PDMS and (f) VG/CNT/PDMS strain sensor.
图4. Optical images of VG/PDMS strain sensor under various strains: (a) initial state, (b) 10%, (c) 20%. Optical images of VG/CNT/PDMS strain sensor under various strains: (d) initial state, (e) 10%, (f) 20%. (g) and (h) SEM image of VG/CNT/PDMS strain sensor under 10% strain. (i) Resistance change of VG/CNT/PDMS strain sensor and theoretical prediction.
图5. Optical images of the VG/PDMS strain sensor at (a) 0% and (b) 50% strain. Optical images of the VG/CNT/PDMS strain sensor at (c) 0% and (d) 50% strain. (e) Schematic of a water droplet on flat or wrinkled and cracked surface. The contact angle of (f) the VG/PDMS strain sensor and (g) the VG/CNT/PDMS strain sensor under 0, 10%, 20%, 50%, 80%, and 100% strains.
图6. Application of the VG/CNT/PDMS strain sensors. The monitoring (a) finger and (b) wrist motion underwater. (c) The detection of fish toy swimming. (d) The integration of VG/CNT/PDMS strain sensor with control unit. The application of the VG/CNT/PDMS strain sensor as a switch in (e) air and (f) water.
图7. (a) The surface temperature of VG/PDMS as a function of time under 5, 7, 10, 12, and 15V respectively. (b) Maximum temperature distribution of VG/PDMS versus voltages respectively. (c) The joule-heating performance of VG/PDMS during cyclic on-off measurements respectively. (d) The surface temperature of VG/CNT/PDMS as a function of time under 5, 7, 10, 12, and 15V respectively. (e) Maximum temperature distribution of VG/CNT/PDMS versus voltages respectively. (f) The joule-heating performance of VG/CNT/PDMS during cyclic on-off measurements respectively.
3小结
受大象象鼻子的皱纹和褶皱启发，我们制备了生物仿生VG/CNT/PDMS复合材料，用于制造高灵敏度和可拉伸的柔性应变传感器。该VG/CNT/PDMS应变传感器展现出高灵敏度系数（GF=1332.5）、显著的线性度（R^2=0.98）、宽广的测量范围（0–100%应变）以及卓越的环境适应性（适用于空气和水下环境）。VG/CNT/PDMS应变传感器的卓越传感性能归因于其独特的皱纹和裂纹形态，以及CNT的桥接效应，从而提升了应变耐受性。此外，VG/CNT/PDMS应变传感器还展现出卓越的多功能性能，包括疏水表面（100%应变时接触角为129°）和焦耳加热能力（在15V电压下2分钟内升温至110.4°C）。所开发的VG/CNT/PDMS应变传感器在人体运动监测和水下开关控制等应用领域展现出巨大潜力，为制备具有优异环境适应性的高性能应变传感器开辟了新途径。
文献：
https://doi.org/10.1016/j.cej.2025.164747
来源：材料分析与应用