Titanium-nickel shape memory alloy (SMA) has good biomedical application value as an implant. Alloy corrosion will promote the release of toxic nickel ions and cause allergies and poisoning of cells and tissues. With this background, surface modification of TiNi SMAs using TiC-powder-assisted micro-electrical discharge machining (EDM) was proposed. This aims to explore the effect of the electrical discharge machining (EDM) parameters and TiC powder concentration on the machining properties and surface characteristics of the TiNi SMA. It was found that the material removal rate (MRR), surface roughness, and thickness of the recast layer increased with an increase in the discharge energy. TiC powder’s addition had a positive effect on increasing the electro-discharge frequency and MRR, reducing the surface roughness, and the maximum MRR and the minimum surface roughness occurred at a mixed powder concentration of 5 g/L. Moreover, the recast layer had good adhesion and high hardness due to metallurgical bonding. XRD analysis found that the machined surface contains CuO₂, TiO₂, and TiC phases, contributing to an increase in the surface microhardness from 258.5 to 438.7 HV, which could be beneficial for wear resistance in biomedical orthodontic applications.

Simultaneously monitoring cortex-wide microvascular dynamics, blood oxygenation metabolism, and neuronal activities with high spatiotemporal resolution is essential for understanding neurovascular coupling (NVC). However, it remains a challenge for existing neuroimaging tools. Here, we report a linear transducer array–based hybrid microscope (LiTA-HM) that integrates photoacoustic microscopy and confocal fluorescence microscopy to achieve simultaneous neurovascular imaging with a field of view (FOV) of 6 millimeters by 5 millimeters, a spatial resolution of ~6 micrometers, and a temporal resolution of 0.8 seconds. We design an array of eight miniature transducers to enlarge FOV and optimize a polygon mirror–based ultrafast scanner to achieve real-time imaging. Proof-of-concept imaging experiments were conducted on awake mice. Different couplings between thousands of neuron somas and vessel branches down to capillaries were observed in hypoxia and anesthesia experiments. Spatiotemporal correlations and functional connectivity in NVC were uncovered for spreading depolarization waves occurred in a drug-induced epilepsy experiment. We expect that LiTA-HM will enable broad applications of neuroimaging.

In this paper, a new style of micro-structured LED (light-emitting diode) diffusion plate was developed using a highly efficient and precise hybrid processing method combined with micro injection molding and micro-grinding technology to realize mass production and low-cost manufacturing of LED lamps with excellent lighting performance. Firstly, the micro-structured mold core with controllable shape accuracy and surface quality was machined by the precision trued V-tip grinding wheel. Then, the micro-structured LED diffusion plate was rapidly fabricated by the micro injection molding technology. Finally, the influences of micro injection molding process parameters on the illumination of the micro-structured diffusion plate were investigated. The simulated optical results show that the illumination of the micro-structured diffusion plate can achieve a maximum value when the V-groove depth and V-groove angle are designed to be 300 μm and 60°, respectively. The experimental results indicate that the developed micro-structured diffusion plate may improve the illumination by about 40.82% compared with the traditional diffusion plate. The prediction accuracy of the designed light efficiency simulation method was about 90.33%.