Large‐scale screening of sequential drug combinations, wherein the dynamic rewiring of intracellular pathways leads to promising therapeutic effects and improvements in quality of life, is essential for personalized medicine to ensure realistic cost and time requirements and less sample consumption. However, the large‐scale screening requires expensive and complicated liquid handling systems for automation and therefore lowers the accessibility to clinicians or biologists, limiting the full potential of sequential drug combinations in clinical applications and academic investigations. Here, a miniaturized platform for high‐throughput combinatorial drug screening that is “pipetting‐free” and scalable for the screening of sequential drug combinations is presented. The platform uses parallel and bottom‐up formation of a heterogeneous drug‐releasing hydrogel microarray by self‐assembly of drug‐laden hydrogel microparticles. This approach eliminates the need for liquid handling systems and time‐consuming operation in high‐throughput large‐scale screening. In addition, the serial replacement of the drug‐releasing microarray‐on‐a‐chip facilitates different drug exchange in each and every microwell in a simple and highly parallel manner, supporting scalable implementation of multistep combinatorial screening. The proposed strategy can be applied to various forms of combinatorial drug screening with limited amounts of samples and resources, which will broaden the use of the large‐scale screening for precision medicine.

The increasing number of potential drug targets and compounds has led to the development of high-throughput cell-based assays. Simultaneous processing of multiple targets in the same experiment based on localized target gene expression is a very efficient strategy for this purpose. To address this need, we present an adenoviral vector-immobilized microparticle with two-dimensional (2D) shape-encoding properties that allows localized patch-like gene delivery to monolayer-cultured cells. This format conveniently achieves multiplexed gene delivery compatible with both high-throughput cellular assays and fluorescence high-content imaging instruments. A multiplex G protein-coupled receptor (GPCR) internalization assay was developed to demonstrate the compatibility of this system with high-throughput image-based cellular assays.

This paper is the first to report a simple and cost‐effective method for modularizing an array of gallium arsenide (GaAs) solar cells on a plastic circuit board using fluidic self‐assembly (FSA) technology and the combination thereof with a polymer lens array to implement micro‐concentrator photovoltaics (micro‐CPV). Using FSA and low‐melting‐point solder, the GaAs cells are successfully self‐assembled into a 2D array in 1 min. Micro‐CPVs consisting of 36 and 256 cells are manufactured by aligning a polymer concentrator fabricated by a drop‐on‐demand droplet dispensed lens array mold on the solar cell array. The micro‐CPVs generate 21.31 and 112.96 mW of power, respectively, under 1 sun AM 1.5G illumination. In each module, only 1.69 and 2.27 mm2 of GaAs are used for producing 1 mW; in other words, the implemented micro‐CPV platform consumes 4.21 and 3.14 times less material than a flat‐panel GaAs array. The proposed method for implementing a GaAs‐based solar cell array enables the efficient fabrication of a compact micro‐CPV with a thickness of only 4 mm owing to the absence of a cooling module. This technology is expected to potentially increase the practical usability of III‐V compound solar cells in the energy industry.

The need for high-throughput screening has led to the miniaturization of the reaction volume of the chamber in bioassays. As the reactor gets smaller, surface tension dominates the gravitational or inertial force, and mixing efficiency decreases in small-scale reactions. Because passive mixing by simple diffusion in tens of microliter-scale volumes takes a long time, active mixing is needed. Here, we report an efficient micromixing method using magnetically rotating microparticles with patterned magnetization induced by magnetic nanoparticle chains. Because the microparticles have magnetization patterning due to fabrication with magnetic nanoparticle chains, the microparticles can rotate along the external rotating magnetic field, causing micromixing. We validated the reaction efficiency by comparing this micromixing method with other mixing methods such as simple diffusion and the use of a rocking shaker at various working volumes. This method has the potential to be widely utilized in suspension assay technology as an efficient mixing strategy.