In this work, an optical contact force sensor for cardiac ablation catheter was developed and preliminarily evaluated. The
working principle and fabrication process of the sensor were easy due to the simplicity of the sensor structure compared
with other available optical sensor technologies. The sensor principle relies on transparent, flexible, and stretchable polymer
layers that contact each under the external force, causing variation in the reflectance depending on the contact area of the
films. PDMS layers for the sensor were prepared by spin-coating and thermal curing, and a cavity was formed on one of the
layers. Finally, these layers were bonded by oxygen plasma treatment and placed on the end-face of a reflectance probe. The
fabricated sensor performed well up to 0.6 gF of applied force with