권성훈 교수

An unclonable, fingerprint-mimicking anti-counterfeiting strategy is presented that encrypts polymeric particles with randomly generated silica film wrinkles. The generated wrinkle codes are as highly unique as human fingerprints and are technically irreproducible. Superior to previous physical unclonable functions, codes are tunable on demand and generable on various geometries. Reliable authentication of real-world products that have these microfingerprints is demonstrated using optical decodi

A rapid antibiotic susceptibility test (AST) is desperately needed in clinical settings for fast and appropriate antibiotic administration. Traditional ASTs, which rely on cell culture, are not suitable for urgent cases of bacterial infection and antibiotic resistance owing to their relatively long test times. We describe a novel AST called single-cell morphological analysis (SCMA) that can determine antimicrobial susceptibility by automatically analyzing and categorizing morphological changes i

A QR-coded microtaggant for the anti-counterfeiting of drugs is proposed that can provide high capacity and error-correction capability. It is fabricated lithographically in a microfluidic channel with special consideration of the island patterns in the QR Code. The microtaggant is incorporated in the drug capsule ("on-dose authentication") and can be read by a simple smartphone QR Code reader application when removed from the capsule and washed free of drug.

Sepsis is one of the major causes of death in the US, necessitating rapid treatment with proper antibiotics. Conventional systems for antibiotic susceptibility testing (AST) take far too long (16-24 h) for the timely treatment of sepsis. This is because they rely on measuring optical density, which relates to bacterial growth, to determine the minimal inhibitory concentrations (MICs) of relevant antibiotics. Thus, there is a desperate need for more improved and rapid AST (RAST) systems. The RAST

DNA-based data storage has emerged as a promising method to satisfy the exponentially increasing demand for information storage. However, practical implementation of DNA-based data storage remains a challenge because of the high cost of data writing through DNA synthesis. Here, we propose the use of degenerate bases as encoding characters in addition to A, C, G, and T, which augments the amount of data that can be stored per length of DNA sequence designed (information capacity) and lowering the

We propose a method for high-throughput generation of 3D microstructures using a membrane-mounted microfluidic channel. Utilizing an optofluidic maskless lithography system, photopolymerized 3D microstructures are fabricated in a layer-by-layer fashion with the thickness of each layer controlled by the deformation of the membrane. The combination of low numerical aperture optical systems for photopolymerization and a soft membrane for height control allows large area projection lithography with

Stereotypic antibody clonotypes exist in healthy individuals and may provide protective immunity against viral infections by neutralization. We observed that 13 of 17 patients with COVID-19 had stereotypic variable heavy chain (V_H) antibody clonotypes directed against the receptor binding domain (RBD) of SARS-CoV-2 spike protein. These antibody clonotypes were composed of immunoglobulin heavy variable 3-53 (<i>IGHV3-53</i>) or <i>IGHV3-66</i> and immunoglobulin heavy joining 6 (<i>IGH

We have designed, fabricated, and demonstrated large vertical displacement vertical microlens scanners with low (<10 V) driving voltage using silicon-on-insulator technology. The unique isolated and pre-engaged vertical comb-drive sets and the coupled-torsion flexure design provide both upward and downward piston motions, as well as low driving voltages. Single-directional devices demonstrate maximum static downward displacement of 8 μm at 10 V/sub dc/. Bidirectional devices demonstrate vertical

DNA-based data storage has attracted attention because of its higher physical density of the data and longer retention time than those of conventional digital data storage. However, previous DNA-based data storage lacked index features and the data quality of storage after a single access was not preserved, obstructing its industrial use. Here, DNA micro-disks, QR-coded micro-sized disks that harbor data-encoded DNA molecules for the efficient management of DNA-based data storage, are proposed.

We have developed a miniature scanning confocal microscope that uses electrostatically actuated microlenses for focusing and scanning. Objective lenses, scanners, a pupil, and a pinhole of the confocal microscope are microfabricated and integrated into a volume smaller than 2 mm3 by stacking these components. Objective lenses are composed of two vertically cascaded polymer microlenses integrated into micromachined comb actuators. Raster scanning is implemented by electrostatically actuating each

Dynamic synthesis of magnetoresponsive structural-colored microspheres is demonstrated by combining an optofluidic approach with a magnetic property tuning method. The strategy allows for the synthesis of magnetochromatic microspheres with controlled and heterogeneous optical properties in a single synthesis environment. Orientation-dependent color diffraction of the magnetochromatic microspheres is utilized to form structural color patterns using a patterned magnet. Detailed facts of importance

Sophisticated three-dimensional (3D) structures found in nature are self-organized by bottom-up natural processes. To artificially construct these complex systems, various bottom-up fabrication methods, designed to transform 2D structures into 3D structures, have been developed as alternatives to conventional top-down lithography processes. We present a different self-organization approach, where we construct microstructures with periodic and ordered, but with random architecture, like mazes. Fo

A method for high-throughput 3D self-assembly of 2D photopatterned microstructures using railed microfluidics is presented. Vertical device patterning of heterogeneous materials requires high-level integration using conventional microelectromechanical system (MEMS) technology; however, 3D railed assembly enables easy and fast self-assembly via a fluidic axis-translation process and simple material exchange in microfluidic channels. Individually photopatterned 2D microstructures are axis-translat