Inflight Fluidic Fibre Printing Towards Array and 3D Optoelectronic and Sensing Architectures

Scalability and device-integration have been prevailing issues limiting our ability in harnessing the full potential of small-diameter conducting fibres. We report inflight fluidic fibre printing, a rapid, low-cost route that integrates the entire process of conducting fibre production and fibre-to-circuit connection, in a single step under sub-100 °C ambient atmospheres. Metallic (silver) or organic (PEDOT:PSS) fibres with 1-3 μm diameter are fabricated, and the fibre arrays exhibit over 95 % transmittance in the 350-750 nm region. We exploit combinations of the unique fibre characteristics: directionality, high surface-area-to-volume ratio, and permissiveness, along with transparency and conductivity. Using PEDOT:PSS fibres as a cell-interfaced impedimetric

sensor and a moisture sensor, we show that even a single fibre component can achieve complex functions or outperform conventional film-based devices. The capability to design suspended fibres and networks of homo-, hetero- cross-junctions, paves the way to applications including

flow-permissive devices, and 3D optoelectronic and sensor architectures.