Direct-ink-writing biosensors: From material innovation to personalized healthcare applications

With the rapid development of wearable and implantable bioelectronics, the requirements in terms of material diversity, structural complexity, and scalable production are progressively increasing. This trend necessitates innovative fabrication methods to overcome the limitations of conventional technologies. Direct ink writing (DIW) printing, a 3D printing technique utilizing shear-thinning inks, has emerged as a promising platform for fabricating next-generation biosensors with customized structures and functions. DIW printing technology has advantages of multi-material compatibility, structural design freedom, high manufacturing efficiency and low cost. This paper reviews the transformative role of DIW printing technology in producing biosensors, with a focus on material innovations, multimodal sensing architectures, and integrated systems that combine energy harvesting, wireless transmission, and decision-making modules. The current challenges faced by DIW printing technology and the possible future directions are also discussed and proposed.