Moulding and Microfluidic Wet Spinning of the Soft Polymer Optical Fibers for Sensory Applications

Polymer optical fibre (POFs) based wearable sensors have attracted a lot of attention in the field of healthcare and biomedical applications. They are in particular envision as the next generation of sensors for the continuous, real-time non-invasive health monitoring of patients in hospitals. In this project, we propose two processing methods, Moulding and Microfluidic wet spinning (MWS) for the production of polymer optical fibres. Polydimethylsiloxane (PDMS) has been chosen as the material of choice for moulding of POFs. PDMS offers versatile properties such as high transparency in the visible-near in-frared spectrum, chemical inertness, flexibility, and tunability of mechanical properties depending on the base to crosslinker and temperature curing conditions. On the other hand, UV and thermally cross-linkable polysiloxanes and acrylic resins have been proposed for MWS of POFs. As preliminary results, flexible PDMS POFs were successfully processed at a different base to crosslinker ratios such as (20:1, 10:1, 5:1) to obtain POFs with variable mechanical and optical properties. The PDMS POFs (10:1) showed an increase in mechanical strength as the curing temperature was increased. On the other hand, PDMS POFs depicted a similar range of light attenuation properties at different curing temperatures.This is an interesting result to process elastic POFs with similar light attenuation properties but different mechanical properties, utilizing the same polymer. The lowest obtained attenuation value was 0.15 dB/cm for moulded PDMS POFs thus far. AFM results reveal a root mean square roughness of 25nm for the moulded PDMS POFs. The further optimization of moulding and development of MWS method to spin POFs is the goal of this project. It is expected to obtain soft polymer optical fibres which may be potentially utilized for sensory applications such as pressure sensing and oxygenation saturation sensing.