3-D Printed Galinstan-Based Capacitive Strain Sensor

In this paper, we present the development of a capacitive strain sensor as a heterogeneous structure. The sensor is designed as a combination of two materials: liquid metal (Galinstan) that was used for making electrodes, and Ecoflex that was used for making isolator and sealant. To fabricate the sensor’s parts, necessary molds were made with 3-D printing technology. The implemented sensor was exposed to a stretch along the x - and y-axis. The capacitance was measured using Hioki IM3590 Impedance analyzer, at a frequency of 10 kHz. The sensitivity of the sensor when stretched along the x-axis in a range of 0 mm to 8 mm, with a step of 2 mm, is $0.108 \mathrm{pF} / \mathrm{mm}$. Along the y-axis the sensor is stretched in a range of 0 mm to 6 mm, with a step of 2 mm, and the obtained sensitivity is $0.183 \mathrm{pF} / \mathrm{mm}$.