Instant interfacial self-assembly for homogeneous nanoparticle monolayer enabled conformal "lift-on" thin film technology

Thin film fabrication is of great importance in modern engineering. Here, we propose a universal and conformal thin film technique enabled by the wetting empowered interfacial self-assembly. By tailoring the contact angle of nanoparticle (NP), a NP monolayer can be assembled instantly (within 5 seconds) with an excellent harvesting efficiency (up to 97.5 weight %). This self-assembly strategy presents a universal applicability on various materials, e.g., nonmetal, metal, and core-shell structures, and can achieve a monolayer with same in-plane area as a 95 cm(2) wafer in a single process, indicating great potential for scale-up manufacturing. Through a template transfer, we coat the surface of different substrates (plastic, paper, etc.) with the assembled film in a conformal and nondestructive "lift-on" manner and subsequently demonstrate fluorescent micropatterns. This self-assembly strategy has great implications in advancing thin film technology in a user-friendly and cost-effective fashion for applications in anti-counterfeiting, actuators, and wearable/flexible electronics.