Jae Jung Kim
Large-scale microparticle arrays (LSMA) are key for material science and bioengineering applications. However, previous approaches suffer from tradeoffs between scalability, precision, specificity, and versatility. Here we present a porous microwell-based approach to create large-scale microparticle arrays with complex motifs. Microparticles are guided to and pushed into microwells by fluid flow through small open pores at the bottom of the porous well arrays. A scaling theory allows for the rational design of LSMAs to sort and array particles based on the size, shape or modulus of the microparticles. Sequential particle assembly allows for proximal and nested particle arrangements, as well as particle recollection and pattern transfer. We demonstrate the capabilities of the technique by applying it to generate a complex, covert tag by the transfer of an upconversion nanocrystal laden LSMA.