Rapid Prototyping of Multi-Scale Electrodes on Polymer Surfaces
Multiscale electrodes that combine features in multiple lengthscales – from the millimetre to the nanometer scale – are essential for developing a wide range of electrical and optoelectronic devices including solar cells1 and biosensors2. While nanomaterials, used in the active region of such devices, have shown to enhance device performance, these often have to be interfaced with wires and contact pads in the milimeter or micrometer lengthscales for use in practical devices3. Although electrodeposition is a simple, inexpensive and rapid method for the fabrication of tunable nanomaterials, it often has to be combined with templates for organizing the nanostructures in the desired device-specific geometries4. Templates created by machining or lithographic processing often add significantly to the complexity and cost of the manufacturing process, and require long design to production times. Self-assembled templates are simple and inexpensive and can be rapidly created; however, they often have shortcomings in terms of controllability of geometry and size5.
Here we demonstrate a facile method for developing multiscale electrodes by combining electrodeposition with templates created using benchtop and rapid prototyping methods. Macroscale patterning is performed using a craft cutter to define electrode patterns on a self-adhesive vinyl film immobilized on a pre-stressed polystyrene substrate. Microscale patterning is induced by shrinking metallic thin films through heating the pre-stressed substrate. Tunable nanostructuring is achieved by manipulating the parameters of the electrodeposition process. The surface structure of these electrodes was characterized using scanning electron microscopy and white light interference microscopy, while their electrical and electrochemical properties were characterized using the four-point-probe and voltammetric methods. The multiscale electrodes fabricated here were shown to be tunable in terms of structure, sheet resistance, and electroactive surface area. Furthermore, complex electrode structures were created for a variety of biomedical applications including electrochemical detection, magnetic separation, and bacterial lysis with a design to fabrication time of a few hours.
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