Recent Advances in Pen-Based Writing Electronics and their Emerging Applications

The emerging demand for cost-effective, easily accessible, and rapid prototyping electronics fabrication calls for novel techniques to design and manufacture electronic components and devices for wearable functional sensing, on-skin medical monitoring, and body-worn energy conversion. Inspired by daily hand-writing, innovative and ubiquitously available pens can be employed to write conductive patterns on multiple substrates; such a low-cost, fast, and user-friendly direct writing paradigm has recently aroused remarkable research interest as a promising electronics prototyping strategy. In this review, state-of-art advances in techniques for direct writing of electronics are presented, and pros and cons of each fabrication route are discussed. Emerging applications of pen-based writing electronics are also summarized. Based on these, final conclusions, limitations and challenges, as well as ongoing perspectives are illustrated.