Fabrication and characterization of gold coated hollow silicon microneedle array for drug delivery

• Published in: Microelectronic engineering Vol. 128; pp. 12 - 18
• Main Authors: Vinayakumar, K.B., Hegde, G.M., Nayak, M.M., Dinesh, N.S, Rajanna, K.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05.10.2014; Elsevier
• Subjects: Applied sciences; Coating; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Drug delivery systems; Dry etching; Electrodeposition, electroplating; Electronics; Electroplating; Etching; Exact sciences and technology; Fluid dynamics; Fluid flow; Inlet pressure; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Microelectronic fabrication (materials and surfaces technology); Microneedles; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silicon; Sputtering; Titanium; Microneedles; Dry etching; Electroplating; Sputtering; Water; Gold; Drug delivery systems; Fluid flow; Skin effect; Coated material; Microelectronic fabrication; Anisotropy; Electrodeposition; Skin; Silicon; Sputter deposition; Arrays; Protective coatings
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2014.05.039

[Display omitted] •Fabrication method for an array of hollow tapered Si microneedles is presented.•Si microneedles biocompatibility is increased by coating Ti &Au.•The breaking force of fabricated microneedles is 10 times above the skin resistive force.•Flow rate variation through microneedles with respect to different inlet pressure is studied. In this paper, we present the fabrication and characterization of Ti and Au coated hollow silicon microneedles for transdermal drug delivery applications. The hollow silicon microneedles are fabricated using isotropic etching followed by anisotropic etching to obtain a tapered tip. Silicon microneedle of 300μm in height, with 130μm outer diameter and 110μm inner diameter at the tip followed by 80μm inner diameter and 160μm outer diameter at the base have been fabricated. In order to improve the biocompatibility of microneedles, the fabricated microneedles were coated with Ti (500nm) by sputtering technique followed by gold coating using electroplating. A breaking force of 225N was obtained for the fabricated microneedles, which is 10 times higher than the skin resistive force. Hence, fabricated microneedles can easily be inserted inside the skin without breakage. The fluid flow through the microneedles was studied for different inlet pressures. A minimum inlet pressure of 0.66kPa was required to achieve a flow rate of 50μl in 2s with de-ionized water as a fluid medium.