Thermally Degradable Inductors with Water-Resistant Metal Leaf/Oleogel Wires and Gelatin/Chitosan Hydrogel Films.

Ingestible electronics monitor biometric information from outside the body. Making them with harmless or digestible materials will contribute to further reducing the burden on the patient's oral intake. Here, considering that the inductive part plays an important role in communications, we demonstrate a degradable inductor fabricated with harmless substances.

Data Processing of SPR Curve Data to Maximize the Extraction of Changes in Electrochemical SPR Measurements.

We developed a novel measuring and data-processing method for performing electrochemical surface plasmon resonance (EC-SPR) on sensor surfaces for which detecting a specific SPR angle is difficult, such as a polymer having a non-uniform thickness with coloration. SPR measurements are used in medicine and basic research as an analytical method capable of molecular detection without labeling. However, SPR is not good for detecting small molecules with small refractive index changes.

Microfluidic Devices Controlled by Machine Learning with Failure Experiments.

A critical microchannel technique is to isolate specific objects, such as cells, in a biological solution. Generally, this particle sorting is achieved by designing a microfluidic device and tuning its control values; however, unpredictable motions of the particle mixture make this approach time-consuming and labor intensive. Here, we show that microfluidic control with reinforced learning characterized by utilizing failure results can maximize the training effect with limited data.

Designing a multilayer film via machine learning of scientific literature.

Scientists who design chemical substances often use materials informatics (MI), a data-driven approach with either computer simulation or artificial intelligence (AI). MI is a valuable technique, but applying it to layered structures is difficult. Most of the proposed computer-aided material search techniques use atomic or molecular simulations, which are limited to small areas.

Thermoresponsive Gelatin/Chitosan Hydrogel Films for a Degradable Capacitor.

Ingestible electronic devices are tools for exploring the condition of the gastrointestinal tract and adjacent organs without a burden on the patients. Making them safe requires that they be fabricated with harmless materials. In this study, we developed a capacitor using food materials for a wireless sensing component.

Direct Measurement of Near-Wall Molecular Transport Rate in a Microchannel and Its Dependence on Diffusivity.

Solute transport in a narrow space is the most elemental process in chromatography and biological pattern formation. However, the observation of such transport has been quite difficult, and theoretical investigations have therefore preponderated. Here, using a space- and time-resolved surface plasmon resonance (SPR) method, we measured the nanoscale near-wall (next to the wall) transport rate in a narrow channel after a solution and its solvent had come into contact.

A reliable aptamer array prepared by repeating inkjet-spotting toward on-site measurement.

A preparation protocol is proposed for a reliable aptamer array utilizing an ink-jet spotter. We accumulated streptavidin and biotinylated-aptamer in this order on a biotinylated-polyethylene glycol-coated gold substrate to prepare an aptamer array. The aptamer array was prepared with an alternate spotting structure where each aptamer spot was placed between reference spots formed with blocking solution thus suppressing contamination from neighboring spots during the blocking and washing processes.

Cooperative suction by vertical capillary array pump for controlling flow profiles of microfluidic sensor chips.

A passive pump consisting of integrated vertical capillaries has been developed for a microfluidic chip as an useful component with an excellent flow volume and flow rate. A fluidic chip built into a passive pump was used by connecting the bottoms of all the capillaries to a top surface consisting of a thin layer channel in the microfluidic chip where the thin layer channel depth was smaller than the capillary radius. As a result the vertical capillaries drew fluid cooperatively rather than independently, thus exerting the maximum suction efficiency at every instance.

Floating chip mounting system driven by repulsive force of permanent magnets for multiple on-site SPR immunoassay measurements.

We have developed a measurement chip installation/removal mechanism for a surface plasmon resonance (SPR) immunoassay analysis instrument designed for frequent testing, which requires a rapid and easy technique for changing chips. The key components of the mechanism are refractive index matching gel coated on the rear of the SPR chip and a float that presses the chip down. The refractive index matching gel made it possible to optically couple the chip and the prism of the SPR instrument easily via elastic deformation with no air bubbles.

Passive fluidic chip composed of integrated vertical capillary tubes developed for on-site SPR immunoassay analysis targeting real samples.

We have successfully developed a surface plasmon resonance (SPR) measurement system for the on-site immunoassay of real samples. The system is composed of a portable SPR instrument (290 mm(W) × 160 mm(D) × 120 mm(H)) and a microfluidic immunoassay chip (16 mm(W) × 16 mm(D) × 4 mm(H)) that needs no external pump system. An integrated vertical capillary tube functions as a large volume (150 μL) passive pump and a waste reservoir that has sufficient capacity for several refill operations.

Effects of surface water on gas sorption capacities of gravimetric sensing layers analyzed by molecular descriptors of organic adsorbates.

The gas sorption capacities of sputtered carbonaceous films are evaluated with quartz crystal resonators. These films are sensitive to 20 ppm organic vapors and exhibit structure-dependent responses. Films derived from synthetic polymers are hydrophobic, whereas films derived from biomaterials are amphiphilic or hydrophilic.

Chirality emergence in thin solid films of amino acids by polarized light from synchrotron radiation and free electron laser.

One of the most attractive hypothesis for the origin of homochirality in terrestrial bioorganic compounds is that a kind of "chiral impulse" as an asymmetric excitation source induced asymmetric reactions on the surfaces of such materials such as meteorites or interstellar dusts prior to the existence of terrestrial life (Cosmic Scenario). To experimentally introduce chiral structure into racemic films of amino acids (alanine, phenylalanine, isovaline, etc.), we irradiated them with linearly polarized light (LPL) from synchrotron radiation and circularly polarized light (CPL) from a free electron laser.

Discriminative detection of volatile sulfur compound mixtures with a plasma-polymerized film-based sensor array installed in a humidity-control system.

We demonstrated the discrimination of volatile sulfur compound mixtures with different mixing ratios by using an array of the plasma-polymerized film (PPF)-coated quartz crystal resonators. The PPF sensor array, which contains PPFs prepared from amino acids and synthetic polymers, exhibited different response patterns to mono or mixed volatile sulfur compounds (VSCs) (hydrogen sulfide and methanethiol) under a dry environment. The sensor array was installed in a desktop-size relative humidity controller.

Aroma sensing and indoor air monitoring by quartz crystal resonators with sensory films prepared by sputtering of biomaterials and sintered polymers.

Thickness shear mode quartz-crystal resonator coated with plasma polymer films (PPFs) produced by radio-frequency sputtering of biomaterials and synthetic polymers were examined with respect to their abilities to continuously monitor indoor air. We confirmed the sensory capabilities of an array of PPF sensors to aromas emitted from essential oils at concentrations as low as the detection threshold of human olfaction. Changes in humidity induced a drift in the response curves of PPF sensors.