In micro-injection molding, polymer/mold interface adhesion may cause severe deformation or damage of micro features on the molded products. To reduce the interface adhesion and improve the molding quality of polymer microfluidic chip, Ni-P-PTFE (polytetrafluoroethylene) ternary composite was adopted to electroform mold insert with self-lubricating properties. The influence of phosphorous acid concentration on the composition and performance of Ni-P-PTFE composites was systematically investigated. Our results demonstrated that the content of P and PTFE particles in the composites raised with an increase in phosphorous acid concentration. Elevated phosphorous acid concentration adversely affected the current efficiency and slowed down the deposition rate, allowing sufficient contact time for PTFE to transfer and adsorb onto the electrode surface. The hardness of the deposited nickel increased from 310 HV to 510 HV in the Ni-P-PTFE composites. Furthermore, the Ni-P-PTFE composites demonstrated excellent self-lubricating properties, showcasing friction coefficients of 0.15 and 0.25 during the initial and steady stages, respectively, representing a notable reduction of 66.7 % and 64.3 % compared to pure nickel. This study provides a novel approach to fabricate molds with self-lubricating properties, which contributes to the high-precision injection molding of polymer-based micro devices.
Polymer microneedles (MNs) attract considerable attention due to their sound biocompatibility and low manufacturing cost. In this study, we prepared polypropylene (PP) MNs utilizing ultrasonic plasticization microinjection molding (UPMIM) technology, and the compression property, piercing performance, and drug infiltration promotion effect of the products were investigated. In addition, we prepared drug-loaded MNs using UPMIM technology and the dip coating method to reveal their drug loading and release properties. Meanwhile, the photothermal properties of polydopamine (PDA) MNs and their in vivo biological application performance in mice were explored. Results showed that PP MNs have good compressive toughness and piercing performance. They can pierce through mice skin, demonstrating good capability in drug infiltration promotion. The drug loading capacity of MNs rose with the increase of the PVA and sucrose contents and dropped with the rise of the temperature, indicating a fast drug release feature. Moreover, PDA MNs showed relatively strong photosensitivity and good cyclic photothermal properties as well as ideal biological application performance, with the mice skin temperature reaching 21.9 °C in 3 min. This research will provide important theoretical and technical support for the manufacturing of polymer MNs and their biological application.
危险品化学品经营许可证（带存储）