Research On Microneedle Forming Die Based On Solid-state Hot Embossing Process

Traditional methods of administration are transdermal and transdermal.The transdermal delivery of micro-needles is effective in combining two drug delivery techniques.As a new type of medical technology,microneedles combine the advantages of traditional methods of administration and overcome their disadvantages.The future applications will become more and more extensive.However,micro-needles are small in size and belong to the micro－scale products,and their molding and mass production mainly depend on micro-molding molds.A micro-molded hot-pressing die was designed to form solid polymer micro-needles.The die was mainly composed of three parts:press-molded parts,temperature control system,and positioning and guidance system.The designed parts structure was cut and hot-pressed.Unified functions,inverted T-type structure will automatically eject the polymer sheet out of the cavity,in order to achieve low-cost polymer micro-needles,mass production to provide solutions.The successful preparation of micro-needles based on polycarbonate(PC)polymers demonstrated that the design of the polymer micro-needles die,the overall structure of the die,the design of the die,and the selection of the die material were reasonable.At the same time,based on lsprepost combined with ansys ls-dyna,the microneedle molding process was simulated.Through the simulation of closed and unenclosed solid microneedle molds,it is proved that the closed solid microneedle mold has better molding effect and the substrate deformation is evener.The hollow micro-needle forming simulation proves that when the upper template die is cylindrical,the hollow micro-needles can be stamped more easily,and increasing the length of the upper die can effectively increase the forming length of the hollow micro-needles.The hollow microneedle forming experiment was designed based on simulation and the effects of temperature,pressure holding time,and whether the substrate material was preheated on the hollow microneedle forming of PC and polypropylene(PP)materials were studied.