Direct nanopatterning of commercially pure titanium with ultra‐nanocrystalline diamond stamps

Abstract

In order to directly imprint features into a hard metal such as titanium, an imprinting stamp composed of material of greater hardness is required. Diamond is the hardest known material, so is an obvious choice for the production of direct‐imprint stamps. Diamond also benefits from a low surface energy, chemical inertness, high resistance to wear and is easily cleaned of contaminants, further favouring it as a stamp material of choice. Chemical vapour deposited ultra‐nanocrystalline diamond (UNCD) provides similar mechanical properties to bulk single crystal diamond and can be deposited across large surface areas. This work examines the use of UNCD as a stamp medium for the transfer of nanoscale features into commercially pure titanium (cpTi) substrates. Development of an efficient and viable method for nanopatterning large, non‐planar cpTi surfaces is highly desirable to control cell adhesion on the surface of bio‐implants. The fabrication of UNCD nanoimprint stamps is detailed and the ability of UNCD to imprint cpTi is illustrated. A square‐ordered matrix of 200 nm diameter pillars over a quarter mm square area are shown to be imprinted with the depth quantified against load (kg). The limitations of the technology are also discussed.

Increased efficiency of direct nanoimprinting on planar and curved bulk titanium through surface modification

“…Detailed information about the material and the stamp fabrication can be found in our earlier paper [16]. The UNCD wafer was scribed into 1 × 1 cm 2 samples and subjected to RCA cleaning (SC-1), followed by ultrasonic solvent cleaning.…”

Nanoimprint technology for patterning functional materials and its applications

“…Moreover, A.I.M. Greer et al performed the direct NIL to construct nanostructures on Ti surface using a diamond stamp [15,16]. Ti was widely adopted in biomedical applications such dental and orthopaedic implants [15][16][17].…”

“…The surface features of the Ti-based implants would influence the cell adhesion property. For example, to precisely control the surface morphologies of the Ti-based implants might help to prevent unwanted cell growth on temporary implants [15]. However, Ti was a relatively hard material that was difficult to pattern.…”

Direct submicron patterning of titanium for bone implants

“…However, most of the EBL methods developed so far for cells guidance have been used to actually create high resolution masters for subsequent patterning of polymeric substrates usually by replica molding and micro/nanoimprinting [1,[9][10][11][12][13]19]. The need of a new master or mold for every different pattern and the difficulty to accurately imprint the patterns into metals [20,21] hinder the possibility to perform systematic research using various well-controlled patterns, and limit generation of a large number of different samples needed for such biological studies. A direct EBL method for Ti patterning would overcome these limitations and eliminate the use of additional imprinting steps.…”