Toyama Industrial Technology Center

In this study, we report high-speed on-chip microgel valves with large displacement, which are suitable for single-cell manipulations. The large displacement and rapid response of the proposed valves are achieved by partially fixing the microgel valves to the substrate, whereas conventional microgel valves are fully fixed to the bottom substrate. By employing this partial fixation, we enhanced the volume expansion ratio from 1.7 to 5.0, leading to a faster response. Moreover, the valves exhibit displacements of several tens of micrometers, making them well suited for single-cell manipulations. These proposed microgel valves are expected to contribute to highthroughput single-cell analysis on a microfluidic chip.

We propose and demonstrate remotely activated (“wireless”) microvalves that utilize the volume change of thermoresponsive gels, induced by the magnetic heating of magnetic nanoparticles (MNPs) embedded within these gels. The thermoresponsive gels were precisely patterned on Si substrates via photolithography. Notably, embedding MNPs in the gels did not compromise the patterning accuracy; the MNP concentration range of 1–3 wt% in the sols (the range of interest in this study) does not strongly affect the swelling behavior of the thermoresponsive gels. The microvalves exhibited strong actuation due to the magnetic heating of the MNPs when subjected to alternating magnetic fields. Our investigation of the valve switching response demonstrated that the opening and closing behavior closely follows the switching of the applied magnetic field.

Abstract The metal additive manufacturing (AM) process allows for the production of three-dimensional (3D) parts with unique geometries that could not be formed by conventional methods. However, our aim is to utilize the AM process to create never-before-seen new materials because we believe it holds potential not only for new processing but also for creating a new material. The TiB2-Fe composite powder developed as a new raw material of the AM process, which was used as an additive powder in additive manufactured (AMed) SUS316L for effectively improving the mechanical properties of AMed SUS316L. The TiB2-reinfoced SUS316L synthesized by a Powder Bed Fusion (PBF) method using the TiB2-Fe composite powder had an extremely high Vickers hardness and strength of about 400 HV and 1250 MPa, respectively, being close to twice those of AMed SUS316L.

We evaluated nanoimprint lithography (NIL) for the fabrication of nanoscale gel robots. In recent years, microrobots have attracted attention because they can be used for micromanipulation. Our group has proposed microgel robots made of thermoresponsive hydrogel that can be assembled and disassembled. However, it is difficult to fabricate those microgel robots in the size of several micrometers that enable us to manipulate cells by previous fabrication process using photolithography. In this paper, we fabricate gel patterns using NIL and investigate its potential for the fabrication of nanoscale gel robots. We succeeded in fabricating an 80 μm circular patterns by NIL.

We designed and actuated a biomimetic micro-gel robot to understand a motion of microorganisms. We fabricated a micro-gel robot with two flagella to reproduce a motion of Chlamydomonas, which is known as model microorganisms. The micro-gel robot is made of temperature-responsive hydrogel (PNIPAAm) mixed with a light absorbing material and can be driven by light irradiation. We decided the design value of robot considering the geometric features of Chlamydomonas and made a difference in concentrations of a light absorber at the root of flagella to realize a breaststroke motion of Chlamydomonas. We successfully actuated a micro-gel robot and compared its motion of flagella to that of Chlamydomonas. Moreover, we succeeded in observation and comparison of the flow around a micro-gel robot and Chlamydomonas.

With the escalating threats in the digital landscape of cybersecurity, the rapid and widespread of masked and phishing URLs poses a significant threat to online users. Detecting these malicious URLs is a paramount concern to safeguard sensitive information and prevent unauthorized access. This study delves into the application of machine learning algorithms for the accurate identification of masked and phishing URLs. Specifically, Decision Tree, Random Forest, and XGBoost algorithms are employed to create predictive models capable of distinguishing between legitimate and malicious URLs. The research involves the collection of a comprehensive dataset comprising both legitimate and various forms of malicious URLs. Feature engineering techniques are applied to extract relevant information from the URLs, transforming them into numerical representations suitable for machine learning. The three selected algorithms are individually trained and finetuned using the dataset, exploiting their unique capabilities to distinguish patterns indicative of phishing attempts and masked URLs. The performance of each model is evaluated using metrics such as accuracy, precision, recall, and web traffic. This study examines the application of machine learning algorithms to identify masked and phishing URLs. By comparing the results of these algorithms, a predictive model capable of distinguishing between legitimate and malicious URLs is created. Experimental results showed promising accuracy rates and potential to contribute to online security efforts. The implications of this research extend to advanced cybersecurity systems, offering enhanced protection against evolving threats in the digital domain.

BackgroundInterprofessional collaboration in the community is becoming essential in primary care, particularly collaboration between public health nurses and general practitioners. However, the precise value of such collaboration has not been sufficiently studied. The purpose of this study was to conduct a qualitative analysis of collaboration between general practitioners and public health nurses in the community to explore the details of the phenomenon and its possible impact on the community.MethodsSince 2015, The University of Toyama has been implementing the Collaborative Health Activities Project, in which general practitioners and public health nurses work together to promote community health. Focus group and individual interviews were conducted with participating staff, and the data were analyzed qualitatively.ResultsFifteen themes were generated, in six categories. The categories were as follows: enhanced roles of public health nurses and physicians in the community, new perspectives on the community, public health nurses' sense of trust and empathy toward physicians, bonds of solidarity between public health nurses and physicians, proactive change in residents, and supporting “hangout places”.ConclusionThe collaboration between general practitioners and public health nurses familiar with the same community fostered a sense of trust and empathy and created the bonds of solidarity between staff and residents. The results also suggest the collaboration may have a positive impact on the local community by inspiring residents to change proactively and supporting “hangouts” where residents and professionals can informally connect.

Fluorine materials exhibit excellent properties, such as high water repellency, low adhesion, and chemical resistance, owing to their low surface energy. They also exhibit high thermal and oxidation stability owing to the strength of the C–F bonds. Recently, in the field of life science, further improvement of the low adherence and antifouling properties of biological substances and microorganisms by imparting surface properties to fluorine materials through pattern fabrication technology has attracted considerable attention. However, fluorine materials exhibit high thermal expansion and contraction, making it difficult to apply fabrication methods, such as injection molding and hot embossing. Conventional focused ion beam and laser processing are difficult for further pattern fabrication. Here, an ultraviolet (UV)-curable material with a high fluorine content (44wt%) was created, and the pattern fabrication of 80-nm line structures was performed on the material by UV nanoimprint lithography using the gas-permeable template that can permeate the gas entrained during pressurization. The water contact angle was 127.3°, with 129.7° being the most favorable, achieved by a combination of the water-repellency characteristics of the UV-curable material with high fluorine content and fine line patterning in the nanometer range. We discovered the possibility of creating surface functions on short-chain perfluoroalkyl sulfonate (PFAS) substitutes with a relatively low impact on the environment and human body by establishing a pattern fabrication method for long-chain PFAS, which is more difficult to pattern fabricate, as a preliminary experiment.

Hydrolyzed hyaluronic acid high-resolution fine microneedles of 13 µm in diameter and 24 µm in height were fabricated from hydrolyzed hyaluronic acid gels made in mixtures of water using vacuum environment imprint lithography processes with a water permeable mold. The gas traps of water and volatile solvents in the imprint materials cause transfer failure in the conventional water impermeable molds of quartz and metal. However, the water permeable mold allows the use of 67 wt% dilution water with high solubility to increase the fluidity of the hydrolyzed hyaluronic acid during the patterning of high-resolution fine microneedles for cosmetics and pharmaceuticals. This demonstration sets a new paradigm of functional pure gels for high-resolution nano-patterning applications with various cosmetic and pharmaceutical materials containing dilution water using a water permeable mold.