Silicon nanowire based ring shape force sensor for sensorized guidewires

This paper presents the development of a ring shaped force sensor for sensorized guidewire applications. The sensor comprises a suspended ring structure located at the center of four suspended beams that can be integrated on the distal tip of a guidewire. SiNWs with a length of 6 μm and a cross section of 90 nm × 90 nm are embedded at the anchor of each silicon bridge as the piezoresistive sensing elements. Taking advantage of the high sensitivity of SiNWs, the fabricated sensor was capable to detect small displacement in nm ranges with a sensitivity of 13.4 × 10^-3 μm^-1 in the z-direction. This force sensor showed high linearity (>99.9%) to the applied load and no obvious hysteresis was observed.