Effects of Sensor Cover Damages on Point Clouds of Automotive Lidar

We investigated the effects of mechanical sensor cover damages like scratches, cracks, and holes on point clouds<br>of automotive lidar.

Effects of Sensor Cover Damages on Point Clouds of Automotive Lidar

We investigated the effects of mechanical sensor cover damages like scratches, cracks, and holes on point clouds<br>of automotive lidar.

Bioinspired Polypyrrole based Fibrillary Artificial Muscle with Actuation and Intrinsic Sensing Capabilities

Artificial muscles comprise a bunch of materials, composites and devices performing a similar behavior to biological muscles, since a mechanical actuation is produced while consuming a certain amount of energy. However, in order to mimic the multiple simultaneous functionalities of the natural muscles, i.e. the proprioception, new devices should be designed. A non-conventional, bioinspired device based on polypyrrole coated electrospun fibrous microstructures, which works simultaneously as artificial muscle and mechanical sensor is reported. A simple fabrication algorithm based on electrospinning, sputtering deposition and electrochemical polymerization produced electroactive aligned ribbon meshes with analogous characteristics as natural muscle fibers. These can simultaneously produce a movement (by applying an electric current/potential) and sense the effort of holding weights (by measuring the potential/current while holding objects up to 24 mg). The amplitude of the movement decreases by increasing the load, a behavior similar with natural muscles. Moreover, when different weights were hanged on the device, it senses the load modification, demonstrating a sensitivity of about 6 mV/mg for oxidation and 3 mV/mg for reduction. These results are important since simultaneous actuation and sensitivity are essential for complex activity. Such devices with multiple functionalities can open new possibilities of applications as smart prosthesis or lifelike robots.

Photonic skins based on flexible organic microlaser arrays

Flexible photonics is rapidly emerging as a promising platform for artificial smart skins to imitate or extend the capabilities of human skins. Organic material systems provide a promising avenue to directly fabricate large-scale flexible device units; however, the versatile fabrication of all-organic integrated devices with desired photonic functionalities remains a great challenge. Here, we develop an effective technique for the mass processing of organic microlaser arrays, which act as sensing units, on the chip of photonic skins. With a bilayer electron-beam direct writing method, we fabricated flexible mechanical sensor networks composed of coupled-cavity single-mode laser sources on pliable polymer substrates. These microlaser-based mechanical sensor chips were subsequently used to recognize hand gestures, showing great potential for artificial skin applications. This work represents a substantial advance toward scalable construction of high-performance and low-cost flexible photonic chips, thus paving the way for the implementation of smart photonic skins into practical applications.

Oxidative Stress-Mediated YAP Dysregulation Contributes to the Pathogenesis of Pemphigus Vulgaris

Pemphigus Vulgaris (PV) is a life-threatening autoimmune disease manifested with blisters in the skin and mucosa and caused by autoantibodies against adhesion protein desmoglein-3 (Dsg3) expressed in epithelial membrane linings of these tissues. Despite many studies, the pathogenesis of PV remains incompletely understood. Recently we have shown Dsg3 plays a role in regulating the yes-associated protein (YAP), a co-transcription factor and mechanical sensor, and constraining reactive oxygen species (ROS). This study investigated the effect of PV sera as well as the anti-Dsg3 antibody AK23 on these molecules. We detected elevated YAP steady-state protein levels in PV cells surrounding blisters and perilesional regions and in keratinocytes treated with PV sera and AK23 with concomitant transient ROS overproduction. Cells treated with hydrogen peroxide also exhibited augmented nuclear YAP accompanied by reduction of Dsg3 and α-catenin, a negative regulator of YAP. As expected, transfection of α-catenin-GFP plasmid rendered YAP export from the nucleus evoked by hydrogen peroxide. In addition, suppression of total YAP was observed in hydrogen peroxide treated cells exposed to antioxidants with enhanced cell-cell adhesion being confirmed by decreased fragmentation in the dispase assay compared to hydrogen peroxide treatment alone. On the other hand, the expression of exogenous YAP disrupted intercellular junction assembly. In contrast, YAP depletion resulted in an inverse effect with augmented expression of junction assembly proteins, including Dsg3 and α-catenin capable of abolishing the effect of AK23 on Dsg3 expression. Finally, inhibition of other kinase pathways, including p38MAPK, also demonstrated suppression of YAP induced by hydrogen peroxide. Furthermore, antioxidant treatment of keratinocytes suppressed PV sera-induced total YAP accumulation. In conclusion, this study suggests that oxidative stress coupled with YAP dysregulation attributes to PV blistering, implying antioxidants may be beneficial in the treatment of PV.

Perancangan Sensor LVDT dan Potensiometer Geser Sederhana Sebagai Alat Potensial Pendeteksi Pergeseran Tanah

A preliminary study on the design of a Linear Variable Differential Transformer (LVDT) sensor and a sliding potentiometer has been carried out. It is a distance measuring sensor that can be used as a ground shift sensor. This study aims to develop a new type of low cost mechanical sensor which has a high enough accuracy. The LVDT sensor is built using affordable materials such as PVC pipes, winding wires and iron cores, which is varied based on the number of primary coil and its diameter. While the potentiometer sensor is prepared by using linear bearing using electrode sheets of nickel and copper which is arranged by implemented the concept of the Newton-Wheatstone Bridge. The measurement value shows that the LVDT sensor with the number of primary coil of 110 and a diameter of 4 mm can measure with an accuracy of 0.5 mm and a range of more than 4 cm. While the sliding potentiometer using a sheet of copper electrodes can measure 0.5 mm with a range of more than 4 cm. The average error shown by the LVDT sensor and the sliding potentiometer is 5.2% and 6.4%, respectively.

Rotaphone-CY: The Newest Rotaphone Model Design and Preliminary Results from Performance Tests with Active Seismic Sources

Rotaphone-CY is a six-component short-period seismograph that is capable of the co-located recording of three translational (ground velocity) components along three orthogonal axes and three rotational (rotation rate) components around the three axes in one device. It is a mechanical sensor system utilizing records from elemental sensors (geophones) arranged in parallel pairs to derive differential motions in the pairs. The pairs are attached to a rigid frame that is anchored to the ground. The model design, the latest one among various Rotaphone designs based on the same principle and presented elsewhere, is briefly introduced. The upgrades of the new model are a 32-bit A/D converter, a more precise placing of the geophones to parallel pairs and a better housing, which protects the instrument from external electromagnetic noise. The instrument is still in a developmental stage. It was tested in a field experiment that took place at the Geophysical Observatory in Fürstenfeldbruck (Germany) in November 2019. Four Rotaphones-CY underwent the huddle-testing phase of the experiment as well as the field-deployment phase, in which the instruments were installed in a small-aperture seismic array of a triangular shape. The preliminary results from this active-source experiment are shown. Rotaphone-CY data are verified, in part, by various approaches: mutual comparison of records from four independent Rotaphone-CY instruments, waveform matching according to rotation-to-translation relations, and comparison to array-derived rotations when applicable. The preliminary results are very promising and they suggest the good functionality of the Rotaphone-CY design. It has been proved that the present Rotaphone-CY model is a reliable instrument for measuring short-period seismic rotations of the amplitudes as small as 10−7 rad/s.