Abstract: On-demand droplet sorting is extensively applied for the efficient manipulation and genome-wide analysis of individual cells. However, state-of-the-art microfluidic chips for droplet sorting still suffer from low Based on the building principle of additive manufacturing, printing orientation mainly determines the tribological properties of joint prostheses. In this study, we created a polyether-ether-ketone (PEEK) joint prosthesis using fused filament fabrication and investigated the effects of printing orientation on its tribological properties using a pin-on-plate tribometer in 25% newborn calf serum. An ultrahigh molecular weight polyethylene transfer film is formed on the surface of PEEK due to the mechanical capture of wear debris by the 3D-printed groove morphology, which is significantly impacted by the printing orientation of PEEK. When the printing orientation was parallel to the sliding direction of friction, the number and size of the transfer film increased due to higher steady stress. This transfer film protected the matrix and reduced the friction coefficient and wear rate of friction pairs by 39.13% and 74.33%, respectively. Furthermore, our findings provide a novel perspective regarding the role of printing orientation in designing knee prostheses, facilitating its practical applications.sorting speeds, sample loss, and labor-intensive preparation procedures. Here, we demonstrate the development of a novel microfluidic chip that integrates droplet generation, on-demand electrostatic droplet charging, and high-throughput sorting. The charging electrode is a copper wire buried above the nozzle of the microchannel, and the deflecting electrode is the phosphate buffered saline in the microchannel, which greatly simplifies the structure and fabrication process of the chip. Moreover, this chip is capable of high-frequency droplet generation and sorting, with a frequency of 11.757 kHz in the drop state. The chip completes the selective charging process via electrostatic induction during droplet generation. On-demand charged microdroplets can arbitrarily move to specific exit channels in a three-dimensional (3D)-deflected electric field, which can be controlled according to user requirements, and the flux of droplet deflection is thereby significantly enhanced. Furthermore, a lossless modification strategy is presented to improve the accuracy of droplet deflection or harvest rate from 97.49% to 99.38% by monitoring the frequency of droplet generation in real time and feeding it back to the charging signal. This chip has great potential for quantitative processing and analysis of single cells for elucidating cell-to-cell variations.

西安交通大学机械工程学院李涤尘教授团队｜3D打印方向对聚醚醚酮人工关节材料的生物摩擦学性能影响