Construction of 3D Patterns Through Modified Electrochemical Replication and Transfer

As the development of flexible electronics continuously progresses, so does the demand for fabricated 3D electrodes via patterning technology. Electrochemical replication and transfer (ERT) has emerged as an efficient patterning technique, which deposits materials of interest on a predefined template via electroplating and subsequently transfers them onto target substrates. ERT can pattern large-area 2D electrodes on nontraditional substrates whilst maintaining adequate flexibility, stretchability, and complex surface structures. This study extends the capability of ERT from 2D into 3D patterning. Via the rational design of a 3D SiO₂/Si template, in which conductive Si trenches or holes are patterned with insulating SiO₂ banks, electroplating of materials only occurs in the exposed Si surfaces so that both continuous and isolated 3D patterns with high aspect ratios up to 4:1 are realized. 3D-ERT offers a high-throughput and low-cost approach to fabricating high Figure of Merit (>30 000) flexible transparent electrodes. Also, the application of 3D-ERT in constructing highly sensitive, and self-powered pressure sensors is showcased.