Jessica Wagner1,Jared Fletcher1,Stephen Morin1,2
University of Nebraska - Lincoln1,University of Nebraska–Lincoln2
Jessica Wagner1,Jared Fletcher1,Stephen Morin1,2
University of Nebraska - Lincoln1,University of Nebraska–Lincoln2
A low-cost and scalable procedure for the deposition of electronic materials onto thin polymeric substrates would be useful to the fabrication of flexible circuits. Traditional fabrication methods such as photolithography and laser-direct structuring are expensive, require long processing steps, and are not readily scalable to 3-dimensional components or flexible polymeric substrates. While electroless deposition is an ideal method for bridging the gap from 2D to 3D fabrication, metal delamination of the deposited films remains a significant problem. We have developed a general approach to increase the adhesion of metal films to commodity plastic substrates using a metal-chelating polymer, polyethyleneimine, in conjunction with patterned electroless deposition. When combined with flexible microfluidic reactors for deposition of different metals and materials (conducting, semi-conducting, etc.), a procedure (microfluidic-directed material deposition or mDMD) for entirely solution-based manufacturing of flexible and non-planar electronics can be realized. We demonstrated the durability of these traces using adhesion tests and mechanical deformations and illustrated the functionality of these metals in simple electronic circuits and electrochemical devices. The ability to deposit different types of materials following the reported procedure allows for the fabrication of flexible circuits with a diversity of functionalities (e.g., optoelectronic, potentiometric, etc). mDMD is compatible with a diverse array of plastics (e.g., PC, PET, PP), metals (e.g., copper, nickel, silver, and gold), and, through the use of chemical bath deposition procedures, semiconductors (e.g., metal chalcogenides and oxides) with properties applicable to flexible electronics, sensors, and electrochemical devices.