image: (a) Schematic of the LISS on the surface of engineering thermoplastics applied in aircrafts. The LISS is composed of sensors, conductive interconnects and signal processing modules. (b) Schematic of LIP-Cu interconnects for LISS fabricated by a continuous wave green laser. (c) Schematic of LIC sensors for LISS fabricated by an infrared laser. Some figure elements were created using BioRender.com.
Credit: Kaichen Xu, Zimo Cai, Huayu Luo, Xingyu Lin, Geng Yang, Haibo Xie, Seung Hwan Ko and Huayong Yang.
Prof. Kaichen Xu and his coworkers from Zhejiang University have developed a novel method to integrate sensor systems directly into engineering thermoplastics using laser technology. Their breakthrough offers the potential for improved safety and extended service life of critical equipment across various industries, including aerospace, automotive, healthcare, and transportation.
The research, published in the International Journal of Extreme Manufacturing (IF: 16.1), introduces a hybrid laser direct writing technique that enables the creation of functional copper interconnects and carbon-based sensors within a single, integrated system. It allows for real-time temperature monitoring over extended periods, ensuring optimal performance and reliability.
The XU research group at ZJU is a highly interdisciplinary research group dedicated to the advanced manufacturing of flexible and conformal electronics for wearable/implantable monitoring in regular or extreme environments. “Our research mainly includes the development of innovative fabrication techniques, multifunctional devices, as well as system level applications. Based on the principle of laser and matter interactions, we focus on manufacturing of versatile devices mainly using hybrid (ultrafast) laser processing platforms, which are endowed with multitasking features.” said Kaichen Xu, corresponding author of this paper.
Integration of sensors with engineering thermoplastics allows to track their health and surrounding stimuli. As one of vital backbones to construct sensor systems, copper (Cu) is highly conductive and cost-effective, yet tends to easily oxidize during and after processing.
Prof. Xu’s group overcame this hurdle by employing a one-step photothermal treatment that results in highly durable Cu interconnects capable of resisting long-term oxidation failure at temperatures up to 170°C. To achieve that, their method involved two key steps: the creation of functional copper (Cu) interconnects through photothermal reduction and passivation of CuO using a continuous wave (CW) laser, and the formation of laser-induced carbon (LIC) sensors from the thermoplastic substrate using an infrared (IR) laser.
The process allowed for the simultaneous reduction, sintering, and passivation of Cu to enhance its oxidation resistance at high temperatures. The integrated sensor system was then tested for its durability and performance in real-time temperature monitoring under various environmental conditions.
Their strategy has significant potential for applications in various fields such as aerospace, automotive, high-speed trains, and medical devices. This system offers a lightweight and durable solution for long-term and real-time monitoring of temperature and other environmental parameters.
As the team continues to refine this technology, they are exploring ways to expand the capabilities of the system to incorporate additional sensing units for parameters like pressure, strain, and humidity. Their ultimate goal is to develop advanced manufacturing techniques to enable high-quality conformal electronics on curved surfaces, moving beyond the current limitations of planar surfaces.
About IJEM:
International Journal of Extreme Manufacturing (IF: 16.1, consecutive 1st in the Engineering, Manufacturing category) is a new multidisciplinary and open-access and double anonymous peer-reviewed journal uniquely covering the full spectrum of extreme manufacturing.
The journal is devoted to publishing original articles and reviews of the highest quality and impact in the areas related to the science and technology of manufacturing functional devices and systems with extreme dimensions (extremely large or small) and/or extreme functionalities, ranging from fundamental science to cutting-edge technologies that support the manufacturing of high-performance products involving emerging techniques and breaking the limits of currently known theories, methods, scales, environments, and performance.
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Journal
International Journal of Extreme Manufacturing
Article Title
An in-situ hybrid laser-induced integrated sensor system with antioxidative copper
Article Publication Date
14-Aug-2024