Colloidal Microdevices-in-Inks towards Ubiquitous Integration on Paper and Textiles

Colloidal devices represent an emerging interdisciplinary frontier, requiring advances in materials science, micro- and nanofabrication, and innovative design strategies. By benefiting from miniaturization, functional microdevices can be fabricated at the scale of pigment microparticles in inks, which are already massively deployed onto omnipresent paper and textile substrates. However, integrating microdevices onto these microfiber substrates remains elusive. Here, we investigate and demonstrate the fabrication, design, and transfer of colloidal microdevices-in-inks onto paper and textiles using contact and non-contact printing and writing methods. The transferred devices preserve their structural integrity and functionality, while exhibiting enhanced, tunable mechanical and optical properties at the nanoscale. This approach introduces new functionalities on fibrous substrates and enables innovative use of conventional writing and printing tools (i.e., ballpoint pens, fountain pens, paintbrushes, and inkjet printers) for scalable and accessible microdevice integration, opening the way to future transfer of chips and microrobotic components.