Build-up of multilayered thin lines using sequential adsorption of polymers in microfluidic channels

There is a constant desire towards the improvement of both the processing and design of new micropatterned circuits to be used in modern technologies, but numerous routes are available to achieve such improvements. We are pursuing new methods to create multilayers self-assembled thin films with high spatial resolution. Our research is based on the coupling of two well-known techniques: Layer-by-Layer (LbL) Assembly and flow in MicroFluidic Networks (μFNs), the latter guiding the multilayer deposition to occur within microchannels. Here, we report on preliminary results regarding the achievement of polymeric multilayer assemblies of poly(sodium-4-styrenesulfonate) and poly(allylamine hydrochloride) with well-defined patterns. Using AFM, we show that steady-state layer-by-layer deposition of our polymers occurs when the solutions are made to flow sequentially through the μFN. The results suggest future capabilities to design assembled structures with control over chain conformation and, eventually, an ability to control the orientation and thickness of the polymeric multilayers.