Inkjet-printed flexible sensors: From function materials, manufacture process, and applications perspective

Recently, novel functional ink materials and printing technologies confer sensors to increasing novel features and facilitate their better integration with wearable, health monitoring, diagnostic medical technologies. Emerging inkjet-printed flexible sensors have attracted much attention for their low-cost, rapid fabrication, and lightweight advantages. The comprehensive summary and analysis of functional materials, fabrication and characterization techniques in the full fabrication process of inkjet printed flexible sensors are of great significance for promoting its vitality and prosperity. Therefore, this paper reviews the recent research progress related to the preparation of flexible sensors by inkjet printing, including key functional materials, inkjet printing fabrication processes, and their applications in wearable health sensing, disease diagnosis, environment and food monitoring. The key fabrication techniques are highlighted, including pretreatment processes, inkjet printing techniques, curing, sintering techniques, characterization techniques, and optimization methods in corresponding scenarios. We also provide a forward-looking perspective on the opportunities and challenges of inkjet printed flexible sensors from practical application to emerging functional ink materials and 3D printing technology in comparison with traditional rigid sensors built on more mature silicon-based materials and manufacturing technologies.