Materials for cosmetic needles: Cosmetic needles must be made of high-strength medical steel, which has strict requirements for rigidity, toughness, yield strength, etc., and complies with national GB18457 regulations; the surface of the material must be drawn smooth; the roughness of the inside of the needle body must be within Ra0.4, and the smoothness and cleanliness of the inside wall are crucial.

Smoothness of blunt cosmetic needles: Usually, the front end of the needle body is designed with an R-shaped semicircular elliptical transition. To facilitate the polishing of the curvature of the guide injection end face, the surface of the needle body must also be polished and repaired. At the rear end of the needle body, sandblasting is recommended to increase the roughness of the bonding surface between the end seat and the adhesive to achieve the strength of the adhesive. Attention should also be paid to the smoothness of the side hole of the blunt needle. The smoothness and safety of its structure is directly related to the performance of the suture line.

Piercing of cosmetic needles: The piercing force of cosmetic microneedles determines the pain of skin contact and the therapeutic effect. With the fine application of needle manufacturing materials and the upgrading and optimisation of needle grinding equipment, cosmetic needles have been greatly improved in terms of sharpness, strength and smoothness. In the future, the application value of needles will be better realised. The surface coating of gold needles on the market also enhances the effect during surgery.

Whether in the selection of materials for cosmetic microneedles or in the design of smooth structures and the satisfaction of surgical requirements, designers of cosmetic microneedles should reasonably design the structures to meet the optimal needs of physicians. We welcome more academic discussions on the application of minimally invasive structures. The content is derived from the experience of the SINOWARES team.