Feasibility Verification and Electrical Performance of Additive-manufactured Flexible Microspiral Inductor Made of Copper Wire

Abstract In recent years, flexible electronic technology has been rapidly developed. Compared with common conductive materials, copper wire has the advantages of high conductivity and low cost. To verify the feasibility of fine copper wire as the conductive material in flexible microelectronic components, a microspiral inductor was taken as an example in this work. First, flexible passive microspiral inductors with 2.5, 4.5, and 6.5 turns were prepared by injection molding using the stereo lithography (SLA) technology to print a mold, with silicone rubber (Ecoflex) as the base material and copper wire as the conductive material. Second, theoretical models of the flexible microspiral inductors with different turns were numerically simulated, and physical experiments on the electrical performance of actual microspiral inductors were conducted under initial and deformation states. The two results were then compared and analyzed. The results showed that the maximum errors in the inductance, quality factor, and self-resonant frequency in the initial state were +18.17%, −19.33%, and 0.17 GHz, and those in the deformation state were +11.15%, −10.88%, and 0.09 GHz. The errors were no more than 20%. These results confirm the feasibility of using copper wire as the conductive material in flexible electronic components.