センサ・マイクロマシン部門誌（論文誌E）では，2014年から英語の論文・レターのみを集めた「英文特集号」を発行しております。これまで，2014～2016年の3月号に，2017～2022年の1月号に掲載されてきました。そして，本年1月号にも特集号を発行することになりました。

This study fabricated and evaluated a Ti blade with a jagged microstructure. The blades were fabricated using photolithography and electrolytic etching. A strongly sharpened edge obtained via undercut etching was fabricated by patterning a thin Au film on the front side of a Ti plate prior to electrolytic etching. The increased undercut length was attributed to an increase in the electric field at the edge of the Au pattern. Consequently, A blade with a jagged microscale structure was fabricated using an optimized process to reduce the friction between each microscale edge and the material being cut. A larger edge indicate a reduction in cutting force. A reduction in the cutting forces parallel to the x- and z-axes was clearly observed for the blade fabricated via electrolytic etching compared with that fabricated using reactive ion etching. The methodology used to control the inclination angle of a microscale edge using an Au pattern is significant for fabricating Ti-based sensors and devices.

The quantification of human grasping mechanism in daily life and sports can lead to the improvement in product functionality and universalization of movement skills. For this purpose, it is necessary to develop a sensor that has sufficient flexibility to deal with complex curved surfaces during grasping and to detect deformations such as bending and twisting, along with the magnitude and direction of the load. In this study, an ultracompact tactile sensor was embedded in a flexible elastomer sheet, and its response to load, bending, and torsional deformation was measured and investigated. As a result, it was demonstrated that this sensor can be used to obtain not only the response to force, but also the magnitude and direction of bending and torsion.

This study reports the development of a nest box that can be used to simultaneously measure changes in the mass and heart rate of a growing seabird chick. The nest box is equipped with two scales and a heart rate monitor. The zero-point drift is expected to be suppressed using two scales. The scale utilizes a noncontact displacement sensor with waterproofing and dustproofing. A silicone tube with one end closed and the other end connected to a pressure sensor is used as a heart monitor. The developed nest box allows noninvasive, sequential measurement of the mass and heart rate of a chick over several months.

In this study a micro-fabrication method is proposed for UV-PDMS, a UV-curable silicone rubber required for flexible polymer MEMS. The three-dimensional backside exposure method for structure fabrication using the flow of liquid UV-PDMS improved the relative patterning error of the dimensions from 40% to 12.5% compared to that with vertical backside exposure. In addition, large-sized specimens consisting of two-dimensional mechanical metamaterial structures were fabricated from UV-PDMS, and the elongation and Poisson’s ratio were evaluated by uniaxial tensile testing. The flexible structure of the metamaterial maintained a Poisson’s ratio near zero.

An ultrasensitive torsional sensor that responds to changes in the quantum spin states of a sample was developed. The beam was fabricated using metallic glass to support the sensor stage and achieve high sensitivity. An experiment was conducted by applying a magnetic field to a magnetic sample mounted on the device stage. By changing the magnetic field at 0.6 mT, torsional movement was observed for the device with NiFe sample placed on the stage, which generated a rotational torque and torsional displacement of 19.6 µm. The validity of the torque was examined by comparing it with theoretical values to eliminate any magnetic moment on the stage.