The Cr-N thin films which are strain sensor material show large gauge factor about not only a longitudinal sensitivity but also a transverse sensitivity. Arranging the film in the perpendicular direction to a strain improves a positional resolution for the strain sensing. In this study, diaphragm type structure for pressure sensor and force sensor has been evaluated by structure analysis, considering arranging the Cr-N thin films to the circumferential direction of the diaphragm. As a result, it was confirmed that the two-sorts of strains along a radial direction and a circumferential direction were generated on the diaphragm. And placing the sensor film in the circumferential direction at the position where the two-sorts of strains show the same sign and the maximum was thought to enlarge the output and to be able to narrow the barrier membrane. Therefore, it was suggested that higher withstanding load and miniaturization of pressure sensor and force sensor consisting of the diaphragm type structure were enabled by arranging the Cr-N thin films to the circumferential direction of the diaphragm.
In this study, we measured the enzymatic activity of acetylcholinesterase (AChE) using the Light Addressable Amperometric Sensor (LAAS), an electrochemical sensor that can easily measure redox current values of multiple samples.
Acetylthiocholine (ATCh) was used as a substrate. ATCh is hydrolyzed by AChE and releases electrons, making it possible to measure current values in accordance with the amount of substrate using LAAS. When KCl solution was used as the supporting electrolyte and an Ag/AgCl reference electrode as the counter electrode, a correlation between substrate concentration and reaction was confirmed in the range of 1µM to 10mM. Malathion was then used as an inhibitor of AChE. Malathion phosphorylates and inactivates AChE, which prevents substrate hydrolysis and is expected to decrease the current value. Experimental results showed a decrease in sensor response correlated with inhibitor concentration.
Direct electrification from low-grade heat is becoming a research focus since those devices are simpler and less bulky in design and package. In our previous studies, we demonstrated a continuous current flow by filling a nanofluids consisting of dodecanethiol coated Au nanoparticles of 3-5 nm in diameter into an inter-electrode gap. Experiments showed that the gap thickness influences the performance of the device and theoretical analysis can relate this to interactions between the nanoparticles and strength variations of the electrical field. In this paper, we report on our efforts on design, fabrication, and evaluation of two types of gaps between metal electrodes of different work functions for the investigation of device performances as well as the operational mechanism. The merits, achievements, as well as process compatibilities of each design will be presented and discussed. The efforts and the results of this work may offer practice applicable nanomanufacturing approaches to fabricating submicron gaps for many other potential applications as well.
In this study, the synergistic effects of photocatalytic reaction and ferroelectric polarization were investigated using the stacked layers of a ferroelectric BaTiO3 and TiO2 photocatalyst. Decolorization of organic dyes was successfully accelerated on the corona polarized BaTiO3/TiO2 layers by simultaneous applying the ultrasonic vibration and light illumination.
This paper addresses the effect of structure on driving characteristics of the tactile pin actuator using Ti-Ni-Cu high formable shape memory alloy (HFSMA) for reaction force variable tactile displays. The actuator has a cross shaped 3D structure as a tactile pin that is convex at the center. When the tactile pin is pushed by a finger, it transforms and generates a reaction force against the finger. According to the superelastic effect of SMA, the reaction force can be changed by monitoring the device temperature, allowing tactile displays to present softness and hardness. We examined the driving characteristics of the actuators with different tactile pin height by simulation and measurement of actual samples. When the tactile pin height was low, the tactile pin was only deformed elasticity and reaction force was not changed with increasing device temperature. On the other hands, when the tactile pin height was large, the tactile pin was deformed with the induced martensitic transformation, and reaction force increased with increasing device temperature. In addition, the reaction force at certain temperature was increased as the tactile pin height increased, which means that this actuator can vary the range of reaction force by changing its tactile pin height.
We developed MEMS tweezers to manipulate an adherent cell, which consists of probes for cell trapping, a comb-drive actuator, and a sensor to detect a dish surface. A double-folded beam was employed as a spring for a large displacement of the probe with stability. Peeling a HeLa cell off from a dish and trapping it were successfully conducted by the MEMS tweezers.
Using the Brillouin optical correlation domain method (BOCDR), distribution measurements and quasi-simultaneous multi-point measurements using a single optical fiber were performed over a 127 m area including three temperature regions: low temperature (-196°C), room temperature (25°C), and high temperature (200°C). The present results show that distributed temperature measurement over a wide temperature range (about 400°C), including room temperature, is possible, and that temperature measurement using Brillouin scattering light has potential applications in the space and other fields.
Since stickiness of skin can cause skin diseases, it is necessary to deal with this problem by using basic cosmetics. However, excessive use of basic cosmetics can worsen adverse skin conditions. In addition, the optimal state of the skin after the use of basic cosmetics has not yet been quantified. In this study, we measured and examined the response to adhesive force using an ultra-compact tactile sensor, and then compared the response to adhesive force of basic cosmetics. As a result, we obtained a response proportional to the strength of the adhesive force. In addition, responses differed greatly depending on the type of basic cosmetics and whether or not there was any residual liquid.
This paper proposes the stress concentration relief fillet of the MEMS cantilever piezoelectric energy harvester (PEH). Stresses at the sharp corner of the beams are quite high due to concentrated stresses, and lead to fracture. We developed a cantilever with the fillet structures using the micro-loading effect. Compared to the typical cantilever PEH, the fracture strength of the beam doubled due to the fillets.