One Step Fabrication of Hollow and Highly Flexible Polydimethylsiloxane Microneedles

Abstract

In this study, the hollow and highly flexible polydimethylsiloxane microneedles were fabricated in a one step and simple design. For this purpose, a commercial dermastamping device (Dermastamp® 140 DRS) was used as a mold to obtain highly flexible PDMS microneedles containing channels. With the proposed design, microneedles with a total height of 1500 μm, 1500 μm center-to-center spacing and 150 μm channel diameter was successfully fabricated. These data are all compatible with the dimensions and the geometry of the mold used. Then, a syringe adapter was fabricated with a 3D printer and combined with the hollow PDMS microneedle patch for the high-throughput production of alginate beads. After the adapter and the hollow PDMS microneedle patch combination was placed into the syringe pump, the mostly spherical alginate beads with a mean diameter of 2.0 ± 0.3 mm was produced. To sum up, the proposed design and fabrication scheme first offer a novel and simple strategy for the fabrication of hollow polymeric microneedles. Moreover, this system has the potential to be used not only for the high-throughput microfluidic fabrication of polymeric beads, but also in controlled drug delivery systems and cell encapsulation studies.

Keywords

• hollow microneedle
• microfabrication
• one step
• polydimethylsiloxane
• alginate beads