Fabrication of Hollow Metal Microneedle Arrays Using a Molding and Electroplating Method
| Autor: | Steven L. Wolfley, Igal Brener, Ryan D. Boehm, Roger J. Narayan, Justin T. Baca, Ronen Polsky, Philip R. Miller, Victor H. Chavez, Matthew W. Moorman, Carlee Erin Ashley |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Fabrication 3D printing 02 engineering and technology Substrate (printing) Molding (process) 010402 general chemistry medicine.disease_cause 01 natural sciences chemistry.chemical_compound Mold medicine General Materials Science Composite material Electroplating Polydimethylsiloxane business.industry Mechanical Engineering 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences chemistry Mechanics of Materials 0210 nano-technology business Layer (electronics) |
| Zdroj: | MRS Advances. 4:1417-1426 |
| ISSN: | 2059-8521 |
| Popis: | The need for hollow microneedle arrays is important for both drug delivery and wearable sensor applications; however, their fabrication poses many challenges. Hollow metal microneedle arrays residing on a flexible metal foil substrate were created by combining additive manufacturing, micromolding, and electroplating approaches in a process we refer to as electromolding. A solid microneedle with inward facing ledge was fabricated with a two photon polymerization (2PP) system utilizing laser direct write (LDW) and then molded with polydimethylsiloxane. These molds were then coated with a seed layer of Ti/Au and subsequently electroplated with pulsed deposition to create hollow microneedles. An inward facing ledge provided a physical blocking platform to restrict deposition of the metal seed layer for creation of the microneedle bore. Various ledge sizes were tested and showed that the resulting seed layer void could be controlled via the ledge length. Mechanical properties of the PDMS mold was adjusted via the precursor ratio to create a more ductile mold that eliminated tip damage to the microneedles upon removal from the molds. Master structures were capable of being molded numerous times and molds were able to be reused. SEM/EDX analysis showed that trace amounts of the PDMS mold were transferred to the metal microneedle upon removal. The microneedle substrate showed a degree of flexibility that withstood over 100 cycles of bending from side to side without damaging. Microneedles were tested for their fracture strength and were capable of puncturing porcine skin and injecting a dye. |
| Databáze: | OpenAIRE |
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