Microfluidic wet spinning of soft polydimethylsiloxane polymer optical fibers

Abstract

Polymer optical fibers (POFs) are an essential component of photonic textile sensors for the development of healthcare@home technologies. However, fabricating tailored POFs exhibiting the required properties for such applications remains challenging. Here, an innovative method to fabricate soft POFs based on polydimethylsiloxane is introduced: the hydrogel-assisted microfluidic wet spinning (HA-MWS) technology. Combined with a straightforward post-processing step, the HA-MWS enabled the production of soft POFs with tailored moduli (0.35 MPa to 5.0 MPa), low surface roughness ( R q < 6 nm), and, consequently, low attenuation (<0.25 dB/cm). The quasi -static and dynamic mechanical, chemical, optical, thermal, and surface properties of the soft POFs produced by HA-MWS were investigated in detail. A photonic textile sensor demonstrator was built with these soft POFs with tailored pressure sensitivity in the range of 2–300 kPa, modulus close to that of skin, and high-temperature stability between -30 C ∘ and 90 C ∘ . This methodology can potentially become a standard tool for designing POFs with tunable properties for healthcare monitoring, soft robotics, and biomedicine applications. • A method was developed for the fabrication of polymer optical fibers (POFs): hydrogel-assisted microfluidic wet spinning. • An extended characterization of the produced POFs was performed and related to their processing and structure. • Soft POFs can have their pressure sensitivity changed by a straightforward post-processing step. • Photonic textiles produced with the soft POFs can reversible sense pressures in the range of 2 to 300 kPa.