Rathod Shasvat, Snowdon Monika, Tino Matthew Peres, Peng Peng
Centre for Advanced Materials Joining, Department of Mechanical and Mechatronics Engineering, University of Waterloo 200 University Avenue West Waterloo Ontario N2L 3G1 Canada
Nanoscale Adv. 2024 Dec 10;7(3):766-783. doi: 10.1039/d4na00463a. eCollection 2025 Jan 28.
Flexible and wearable devices play a pivotal role in the realm of smart portable electronics due to their diverse applications in healthcare monitoring, soft robotics, human-machine interfaces, and artificial intelligence. Nonetheless, the extensive integration of intelligent wearable sensors into mass production faces challenges within a resource-limited environment, necessitating low-cost manufacturing, high reliability, stability, and multi-functionality. In this study, a cost-effective fiber laser direct writing method (fLDW) was illustrated to create highly responsive and robust flexible sensors. These sensors integrate laser-induced graphene (LiG) with mixed metal oxides on a flexible polyimide film. fLDW simplifies the synthesis of graphene, functionalization of carbon structures into graphene oxides and reduced graphene oxides, and deposition of metal-oxide nanoparticles within a single experimental laser writing setup. The preparation and surface modification of dense oxygenated graphene networks and semiconducting metal oxide nanoparticles (CuO , ZnO , FeO ) enables rapid fabrication of LiG/MO composite sensors with the ability to detect and differentiate various stimuli, including visible light, UV light, temperature, humidity, and magnetic fluxes. Further, this customizability of fLDW-produced sensors allows for tunable sensitivity, response time, recovery time, and selectivity. The normalized current gain of resistive LiG/MO sensors can be controlled between -2.7 to 3.5, with response times ranging from 0.02 to 15 s, and recovery times from 0.04 to 6 s. Furthermore, the programmable properties showed great endurance after 200 days in air and extended bend cycles. Collectively, these LiG/MO sensors stand as a testament to the effectiveness of fLDW in economically mass-producing flexible and wearable electronic devices to meet the explicit demands of the Internet of Things.
柔性可穿戴设备在智能便携式电子产品领域发挥着关键作用，因为它们在医疗监测、软体机器人、人机界面和人工智能等方面有多种应用。尽管如此，在资源有限的环境中，将智能可穿戴传感器广泛集成到大规模生产中面临挑战，这就需要低成本制造、高可靠性、稳定性和多功能性。在本研究中，展示了一种具有成本效益的光纤激光直写方法（fLDW）来制造高响应性和坚固的柔性传感器。这些传感器在柔性聚酰亚胺薄膜上集成了激光诱导石墨烯（LiG）和混合金属氧化物。fLDW简化了石墨烯的合成、将碳结构官能化为氧化石墨烯和还原氧化石墨烯，以及在单个实验激光写入装置中沉积金属氧化物纳米颗粒的过程。致密氧化石墨烯网络和半导体金属氧化物纳米颗粒（CuO 、ZnO 、FeO ）的制备和表面改性使得能够快速制造LiG/MO 复合传感器，该传感器能够检测和区分各种刺激，包括可见光、紫外线、温度、湿度和磁通量。此外，fLDW生产的传感器的这种可定制性允许调整灵敏度、响应时间、恢复时间和选择性。电阻式LiG/MO 传感器的归一化电流增益可控制在-2.7至3.5之间，响应时间为0.02至15秒，恢复时间为0.04至6秒。此外，可编程特性在空气中放置200天和经过多次弯曲循环后仍表现出很强的耐久性。总的来说，这些LiG/MO 传感器证明了fLDW在经济地大规模生产柔性可穿戴电子设备以满足物联网明确需求方面的有效性。
