Barja Aida M, Ryu Yu Kyoung, Tarancón Sandra, Tejado Elena, Hamada Assia, Velasco Andres, Martinez Javier
Instituto de Sistemas Optoelectrónicos y Microtecnología, Universidad Politécnica de Madrid, Av. Complutense 30, Madrid 28040, Spain.
Departamento de Física Aplicada e Ingeniería de Materiales, E.T.S.I Industriales, Universidad Politécnica de Madrid, C/José Gutiérrez Abascal 2, 28006 Madrid, Spain.
ACS Omega. 2024 Aug 30;9(37):38359-38370. doi: 10.1021/acsomega.3c09067. eCollection 2024 Sep 17.
To enable the development of artificial intelligence of things, the improvement of the strain sensing mechanisms and optimization of the interconnections are needed. Direct laser writing to obtain laser-induced graphene (LIG) is being studied as a promising technique for producing wearable, lightweight, highly sensitive, and reliable strain sensors. These devices show a higher degree of flexibility and stretchability when transferred to an elastomeric substrate. In this article, we manufactured polydimethylsiloxane (PDMS)-encapsulated LIG piezoresistive strain sensors with a quasi-linear behavior and a gauge factor of 111. The produced LIG was morphologically characterized via Raman spectroscopy and scanning electron microscopy before and after the electromechanical characterization and before and after the LIG transfer to PDMS. The results from these analyses revealed that the integrity of the material after the test was not affected and that the LIG volume in contact with the substrate increased after transfer and encapsulation in PDMS, leading to the improvement of the sensor performance. The sensors' capability for measuring bend angles accurately was demonstrated experimentally, making them useable in a wide range of applications for human body movement monitoring as well as for structural health monitoring. Regarding body monitoring, a PDMS-encapsulated LIG sensor for knee bending angle detection was proposed. This device showed unaffected performance of 1500 cycles under 8% uniaxial deformation and with response times in the range of 1-2 s.
为了推动物联网人工智能的发展，需要改进应变传感机制并优化互连。直接激光写入以获得激光诱导石墨烯（LIG）作为一种用于生产可穿戴、轻质、高灵敏度和可靠应变传感器的有前途的技术正在被研究。当转移到弹性体基板上时，这些器件表现出更高程度的柔韧性和可拉伸性。在本文中，我们制造了具有准线性行为和111的应变系数的聚二甲基硅氧烷（PDMS）封装的LIG压阻式应变传感器。在机电表征前后以及LIG转移到PDMS前后，通过拉曼光谱和扫描电子显微镜对所制备的LIG进行了形态表征。这些分析结果表明，测试后材料的完整性未受影响，并且在转移并封装到PDMS中后，与基板接触的LIG体积增加，从而导致传感器性能的提高。通过实验证明了传感器准确测量弯曲角度的能力，使其可用于人体运动监测以及结构健康监测的广泛应用中。关于人体监测，提出了一种用于检测膝盖弯曲角度的PDMS封装的LIG传感器。该器件在8%的单轴变形下表现出1500次循环的不受影响的性能，响应时间在1-2秒范围内。
