To develop a wearable multi-lead electrocardiogram (ECG) measuring system, we fabricated the electrodes and wires by using electrostatic flocking technology on a textile. By using this technology, it was possible to fabricate many electrodes and wires, simultaneously. Also the flocked electrodes and wires had stretchability and washing resistance properties. To use dry electrodes, it is important to reduce the influence of motion artifacts (MAs). The results of the experiment with the skin phantom revealed that the contact pressure between the skin and the electrode is an important factor in MA reduction. Then, we conducted experiments with a human body to determine the relationship between the contact pressure and the MAs. Under the pressures of 200 Pa and 500 Pa, MAs were observed. Meanwhile, under the pressures of 1000 Pa, 2000Pa and 4000 Pa, the ECG signals under rest and deep breathing conditions were able to be measured without MAs. Considering the comfortability, the contact pressure from 1000 Pa to 2000 is preferable. Finally, we fabricated the wearable ECG measuring system and succeeded in measuring 18-lead ECG signals. The measured ECG waveform is in good agreement with the ECG waveform measured by a commercial system.

Conventional electromagnetic microelectromechanical system scanners require a biaxial (two-axis) external magnetic field to obtain a biaxial torque, which increases the number of bulky external permanent magnets and the packaging size caused by 45 $^{\circ}$ -orientated placement of permanent magnets. Thus, this study developed a two-axis resonant electromagnetic scanner with an asymmetric gimbal frame that generates two-axis torque via a one-axis lateral external magnetic field. As external permanent magnets can be placed parallel to the device die, the proposed method reduced the packaging size. Two driving forces were generated by two independent electromagnetic actuators placed on both sides of the asymmetric gimbal frame, which converted the unidirectional forces into two-axis torque. As the two driving actuators were independent of the connecting beams, gimbal frame, and mirror and were connected to the thick outer Si handle frame, the temperature increase of torsion beams and the asymmetric gimbal frame, which affects the resonant performance, were reduced. Additionally, as the current paths were not multiturn coil shapes, the paths can be formed with a via-less single metal layer. Also, the drive circuit can be simplified since drive signals for two-axis rotation can be applied to individual actuators. We demonstrated biaxial scanning using the proposed structure with a 4-mm mirror. The optical scanning angle was 4.84 $^{\circ}$ for the 1.308 kHz X-axis scan and 16.1 $^{\circ}$ for the 2.568 kHz Y-axis scan when a current of 300 mA was applied independently to the X-and Y-axes driving actuators. We obtained the large displacement at the resonant frequency using the asymmetric gimbal frame under a lateral magnetic field. 2024-0050

We describe the fabrication and evaluation of a nail-deformation haptics actuator having a flexible haptics film. The novelty of the developed actuator is the generation of a vibration that directly deforms the nail and finger pad. The flexible piezo-MEMS film is fabricated adopting ultra-thin lead-zirconate-titanate microelectromechanical system (MEMS) and lamination technology. The flexible piezo-MEMS film has flexibility (thickness: 65 μ m) and low weight (mass: 55 mg). The device can thus be attached on a nail without discomfort. A nail-deformation haptics actuator was fabricated by attaching this flexible piezo-MEMS film on an artificial nail. When applying a DC voltage of 40 V to the film, there was a strain of −36.5 × 10 ⁻⁶ in the cylindrical direction of the nail and −12.1 × 10 ⁻⁶ in the circumferential direction. Furthermore, applying an AC voltage (40 V _pp , 20 V _offset ) at a frequency of 200–300 Hz, the finger pad deformed sufficiently to perceive vibration.

This study aims to represent fine texture differences in pencil hardness using intensity segment modulation (ISM), a sensory equivalent conversion method of vibration from high to low frequencies. This method enables the presentation of delicate tactile sensations even with small transducers. We integrated this approach in the world's thinnest ultra-thin PZT-MEMS vibrator with a stylus-type device. The vibration waveforms of four types of pencil hardness were captured under the same conditions, and the differences in the frequency components were confirmed. We compared the fine texture feelings under raw signal, ISM, and ISM below 1 kHz conditions by conducting discrimination tests and subjective similarity evaluations. The results showed that ISM could reproduce similar feelings of the pencil hardness.

We realized the implementation of an ultrathin piezoresistive Si chip and stretchable printed wires on a flexible film substrate using simple screen-offset printing technology. This process does not require a special MEMS fabrication equipment and is applicable to face-up chips where electrodes are formed on the top surface of the chip, as well as to face-down chips where electrodes are formed on the bottom surface of the chip. This fabrication process is quite useful in the field of flexible hybrid electronics (FHE) as a method for mounting and wiring electronic components on a flexible substrate. In this study, we confirmed that face-up and face-down chips could be mounted on polyimide film tape. Furthermore, it was confirmed that the two types of chips could be simultaneously mounted even if they exist on the same substrate. Five-μm-thick piezoresistive Si chips were transferred and wired on a polyimide film tape using screen-offset printing, and a band-plaster type blood pulse sensor was fabricated. Moreover, we successfully demonstrated that the blood pulse could be measured with neck, inner elbow, wrist, and ankle.