김재용 교수

Hydrochromic materials have been actively investigated in the context of humidity sensing and measuring water contents in organic solvents. Here we report a sensor system that undergoes a brilliant blue-to-red colour transition as well as ‘Turn-On’ fluorescence upon exposure to water. Introduction of a hygroscopic element into a supramolecularly assembled polydiacetylene results in a hydrochromic conjugated polymer that is rapidly responsive (<20 μs), spin-coatable and inkjet-compatible. Importa

In this paper, we describe angular vertical-comb-drive torsional microactuators made in a new process that induces residual plastic deformation of single-crystal-silicon torsion bars. Critical dimensions of the vertically interdigitated moving-and fixed-comb actuators are self-aligned in the fabrication process and processed devices operate stably over a range of actuation voltages. We demonstrate MEMS scanning mirrors that resonate at 2.95kHz and achieve optical scan angles up to 19.2 degrees w

Broadband light absorbers are highly desirable in various applications including solar-energy harvesting, thermo-photovoltaics, and photon detection. The Fabry–Perot (F–P) cavity comprising metal–insulator–metal (MIM) layers has attracted enormous interest as a lithography-free structure for realizing planar super absorbers. However, typical F–P cavity exhibits a narrow absorption band, and efforts have thus been made to increase the absorption bandwidth. This study demonstrates that near-perfec

Owing to its high conductivity, solution processability, mechanical flexibility, and transparency, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been extensively explored for use in functional devices including solar cells, sensors, light-emitting diodes, and supercapacitors. The ability to fabricate patterned PEDOT:PSS on a solid substrate is of significant importance to develop practical applications of this conducting polymer. Herein, we describe a new approach to ob

This paper studies practical consensus (PC) problem for linear multi-agent systems (MAS) under a fixed, connected, and undirected communication network. PC means that the difference between any two agents remains in an arbitrarily chosen neighborhood of the origin after some time by using a suitable control law. All the agents, which are heterogeneous first-order linear time-varying (LTV) systems, can collect only relative state information from their neighborhoods. According to the assumptions

We developed a promising mRNA vaccine against severe fever with thrombocytopenia syndrome (SFTS), an infectious disease caused by the SFTS virus that is primarily transmitted through tick bites. Administration of lipid nanoparticle-encapsulated mRNA-Gn successfully induced neutralizing antibodies and T-cell responses in mice. The vaccinated mice were protected against a lethal SFTS virus challenge, suggesting that this mRNA vaccine may be an effective and successful SFTS vaccine candidate.

An azobenzene-containing supramolecular polydiacetylene (PDA) crystal undergoes a photoinduced reversible blue-to-red phase transition accompanied by crystal tearing.

We designed and implemented a fork-type automatic guided vehicle (AGV) with a laser guidance system. Most previous AGVs have used two types of guidance systems: magnetgyro and wire guidance. However, these guidance systems have high costs, are difficult to maintain with changes in the operating environment, and can drive only a pre-determined path with installed sensors. A laser guidance system was developed for addressing these issues, but limitations including slow response time and low accura

This paper studies a design and analysis of distributed Kalman-Bucy filter in sensor networks. When observability of the target system from each sensor is lost, boundedness of the covariance matrices for the individual Riccati equations are not guaranteed. In order to overcome this difficulty and to recover the optimality of the centralized Kalman-Bucy filter, we introduce exchange of covariance matrices with other agents. Then, since those Riccati equations and estimators are heterogenous, achi

Severe fever with thrombocytopenia syndrome virus was first discovered in 2009 as the causative agent of severe fever with thrombocytopenia syndrome. Despite its potential threat to public health, no prophylactic vaccine is yet available. This study developed a heterologous prime-boost strategy comprising priming with recombinant replication-deficient human adenovirus type 5 (rAd5) expressing the surface glycoprotein, Gn, and boosting with Gn protein. This vaccination regimen induced balanced Th

FAαPbBr2+α composite perovskites consisting of 0D FA4PbBr6 and 3D FAPbBr3 have been synthesized by a solid state reaction. Due to the endotaxy passivation of FAPbBr3 by FA4PbBr6, FAPbBr3 crystals were stably deformed without agglomeration from the cubic to the orthorhombic structure by compression, which led to a significant PL enhancement.

Supramolecular polymer films can be formed by DNA-based reversible polymers on a surface with grafted anchor points (see Figure). The adhesive mechanical properties of the self-assembled polymer brushes have been investigated by atomic force microscopy. Reversible polymer-mediated adhesion is found to be sensitive to surface anchor density and the thermodynamics and conformational flexibility of the monomer in this system.