Polymer-assisted metal deposition (PAMD ) for Soft Electronics

One solution-processible strategy, namely polymer-assisted metal deposition (PAMD), has been developed in our group, which allows ambient fabrication of flexible, foldable, stretchable, compressible, and wearable metal (especially Cu) conductors with very high conductivity. As shown in Figure 1, the key innovation of PAMD is the use of a thin and functional polymer interfacial layer that assists electroless deposition (ELD) of metal thin films and patterns (Au, Ag, Cu, and Ni) on soft substrates such as plastics, elastomers, papers, and polyurethane sponges. Such a polymer interfacial layer offers remarkable adhesion between metal and substrate, which is critical for enhancing the mechanical durability of the metal layer upon large deformation. In general, PAMD includes three steps. First, fundtional interfacial polymer such as (i.e., poly[2-(methacryloyloxy)ethyl] trimethylammonium chloride (PMETAC)) are anchored on various substrates at ambient conditions. And then, the catalyst precusors are immobilized into the polymer layer by ion exchange. Finally, the ELD process is proformed and corresponding thin metal films are obtained. Importantly, PAMD is compatible with versatile substrates. Moreover, the patterned metal films can be readily fabricated by patterning the PMETAC nanoplatform or catalyst precusors. On the basis of these advantages, PAMD is employed to fabricate flexible, foldable, stretchable, and wearable metal conducting sheets (Figure 1a), patterned flexible and stretchable metal interconnects (Figure 1b), and stretchable and compressible 3D metal sponges (Figure 1c), respectively.