Twisting patterning: electrochemical deposition of stretchable spiral metallic conductors on elastic polymer threads†
A twisting patterning process is developed to fabricate spring-like 3D stretchable metallic conductors on elastic threads. This process follows steps of thread twisting, catalyst spraying and electrochemical deposition of metal to prepare a thick metallic spiral coiled on a thread surface. The prepared spiral conductor is highly stretchable with a pure metal conductivity (5.76 μΩ cm using a combinative metal layer of gold, copper and nickel), a low resistance (about 0.1 Ω per centimeter) and an extremely high resistance stability when stretching (<3% resistance fluctuation at the strain lower than 100%), so it is quite appropriate to connect electronic components in stretchable devices. Double parallel metallic spirals can be prepared on a single thread, so the input and output of current can be achieved using one thread. Multi-spiral patterns with different spiral styles can also be prepared on a single thread to form a specific circuit bonded with functional components, and the whole device is obtained in a thread form. In addition, the inductance of the spring-like conductor shows an increase while stretching and a decrease while bending, indicating potential applications on tension and bending detection.