| Ion Beam Texturing
A variety of surface morphologies are possible, ranging from random conical structures with sharp points to uniformly spaced square columns with flat tops. The surface features are durable because they are integral to the substrate.
The process uses a mask to crate a pattern on the substrate, and remove-surface material from unasked areas. Three masking methodologies exist:
- Natural seeding takes advantage of the natural variation in the substrate material. Because of these variations, sputter yields vary and random spacing of the features occurs.
- Random seeding creates a random pattern of features when natural seeding fails. Feature density and distribution can be more closely controlled.
- Interval seeding can be used to create a uniformly spaced pattern on a material.
Ion beam texturing is a biocompatible process and can be used for various applications which require surface modification to improve adhesion, enhance tissue ingrowth, or increased electrical-charge transfer.
Current biomedical applications include peritoneal implants, soft tissue implants, hydrocephalic shunts, percutaneous connectors, dental implants, and orthopedic prostheses. One particular use is that of texturing pacemaker electrode tips to improve the threshold for pulsing and increase battery life.
Ion beam texturing is accomplished using a high energy beam to selectively remove material from the substrate. Shown is a fine-mesh mask, which restricts the ablating of material to define (unmasked) areas. Natural and random seeding are alternative masking choices.
Ion beam texturing results in surface morphologies with finer resolution than can be achieved with the use of laser beams.
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