Mechanical behavior and microstructure of porcine brain tissues under pulsed electric fields.

Pulsed electric fields are extensively utilized in clinical treatments, such as subthalamic deep brain stimulation, where electric field loading is in direct contact with brain tissue. However, the alterations in brain tissue's mechanical properties and microstructure due to changes in electric field parameters have not received adequate attention. In this study, the mechanical properties and microstructure of the brain tissue under pulsed electric fields were focused on. Herein, a custom indentation device was equipped with a module for electric field loading. Parameters such as pulse amplitude and frequency were adjusted. The results demonstrated that following an indentation process lasting 5 s and reaching a depth of 1000 µm, and a relaxation process of 175 s, the average shear modulus of brain tissue was reduced, and viscosity decreased. At the same amplitude, high-frequency pulsed electric fields had a smaller effect on brain tissue than low-frequency ones. Furthermore, pulsed electric fields induced cell polarization and reduced the proteoglycan concentration in brain tissue. As pulse frequency increased, cell polarization diminished, and proteoglycan concentration decreased significantly. High-frequency pulsed electric fields applied to brain tissue were found to reduce impedance fluctuation amplitude. This study revealed the effect of pulsed electric fields on the mechanical properties and microstructure of ex vivo brain tissue, providing essential information to promote the advancement of brain tissue electrotherapy in clinical settings.

Fabrication of Laser-Induced Graphene Based Flexible Sensors Using 355 nm Ultraviolet Laser and Their Application in Human-Computer Interaction System.

In recent years, flexible sensors based on laser-induced graphene (LIG) have played an important role in areas such as smart healthcare, smart skin, and wearable devices. This paper presents the fabrication of flexible sensors based on LIG technology and their applications in human-computer interaction (HCI) systems. Firstly, LIG with a sheet resistance as low as 4.5 Ω per square was generated through direct laser interaction with commercial polyimide (PI) film. The flexible sensors were then fabricated through a one-step method using the as-prepared LIG. The applications of the flexible sensors were demonstrated by an HCI system, which was fabricated through the integration of the flexible sensors and a flexible glove. The as-prepared HCI system could detect the bending motions of different fingers and translate them into the movements of the mouse on the computer screen. At the end of the paper, a demonstration of the HCI system is presented in which words were typed on a computer screen through the bending motion of the fingers. The newly designed LIG-based flexible HCI system can be used by persons with limited mobility to control a virtual keyboard or mouse pointer, thus enhancing their accessibility and independence in the digital realm.

Calibration point distribution study of a four-wheel alignment optimization device based on a blanket technology algorithm.

Optimal wheel alignment improves fuel efficiency, safety, and driver comfort. An explicit formula for determining kingpin parameters, namely, caster and kingpin inclination angle (KIA), in four-wheel alignment is lacking. Currently, caster and KIA values are estimated by repetitive large-scale computing with a mathematical model aimed at obtaining values infinitely close to real solutions. In this study, a four-wheel aligner calibration device was used to collect large amounts of data for a variety of four-wheel aligner measurements with a short data interval. The data were subjected to the local fractal dimension analysis with fractional dimension-based blanket technology (BT) to optimize the number of measurement points. Dramatic changes in data were attributable to local areas with a large fractional number dimension. Appropriate increase in the number of calibration measuring points in areas with a relatively low fractional number dimension can reduce the overall quantity of measuring points. The results provide a scientific basis for the development of alignment calibration standards and demonstrate that these parameters can be assessed based on a small number of measurements. Our BT-based methodology can facilitate factory inspection and performance testing of four-wheel aligners and may improve the accuracy of wheel positioning parameter assessments.