Recent developments in selective laser processes for wearable devices

Recently, the increasing interest in wearable technology for personal healthcare and smart virtual/augmented reality applications has led to the development of facile fabrication methods. Lasers have long been used to develop original solutions to such challenging technological problems due to their remote, sterile, rapid, and site-selective processing of materials. In this review, recent developments in relevant laser processes are summarized under two separate categories. First, transformative approaches, such as for laser-induced graphene, are introduced. In addition to design optimization and the alteration of a native substrate, the latest advances under a transformative approach now enable more complex material compositions and multilayer device configurations through the simultaneous transformation of heterogeneous precursors, or the sequential addition of functional layers coupled with other electronic elements. In addition, the more conventional laser techniques, such as ablation, sintering, and synthesis, can still be used to enhance the functionality of an entire system through the expansion of applicable materials and the adoption of new mechanisms. Later, various wearable device components developed through the corresponding laser processes are discussed, with an emphasis on chemical/physical sensors and energy devices. In addition, special attention is given to applications that use multiple laser sources or processes, which lay the foundation for the all-laser fabrication of wearable devices. Graphic abstract