Biomaterials are being investigated to produce platform as scaffolds for cell/tissue growth and differentiation/regeneration. Cell-materials, chemical and biological interactions enable the application of more functional materials in the area of bioengineering, providing a pathway to novel treatment of humans suffering from tissue/organ damage and facing limitation of donation organs. Many studies were done on the tissue/organ regeneration. Development of new scaffolds for cell/tissue regeneration is a key R&D field. This chapter focuses on describing R&D on the novel ultrananocrystalline diamond (UNCD) film as a unique biomaterial for scaffolds for developmental biology. Recent research showed that cells grown on the surface of UNCD-coated culture dishes are similar to cell culture dishes with little retardation, indicating UNCD films have no or little inhibition on cell proliferation and are potentially appealing as substrate/scaffold materials. The mechanisms of cell adhesion on UNCD surfaces are proposed based on the experimental results. The comparisons of cell cultures on diamond-powder-seeded culture dishes and on UNCD-coated dishes with matrix-assisted laser desorption/ionization - time-of-flight mass spectroscopy (MALDI-TOF MS) and X-ray photoelectron spectroscopy (XPS) analyses provided valuable data to support the mechanisms proposed to explain the adhesion and proliferation of cells on the surface of UNCD scaffolds.

This chapter focuses on describing the work done to develop UNCD films as hermetic, bio-inert/biocompatible (made of C atoms-element of life in human DNA) coatings for encapsulation of Si-based microchips implantable inside the eye on the human retina, as the main component of an artificial retina to restore partial vision to people blinded by genetically-induced degeneration of the retina photoreceptors. The UNCD coating enables implantation of the Si microchips inside the eye, since diamond is totally inert to chemical attack by the eye humor, as opposed to Si, which is chemically etched. The chapter describes the synthesis of the UNCD films with focus on using a novel low temperature (≤ 400 ˚C) UNCD growth process to make it compatible with encapsulation of the Si microchip without destroying the CMOS transistors, in the chip, which exhibit a thermal budget of 400 ˚C, i.e., they cannot be heated beyond those temperatures since they would be destroyed. The chapter also the extremely smooth and dense surface needed for the UNCD coating to be hermetic.

This chapter describes the fundamental and applied science underlying the synthesis of UNCD films, using microwave plasma chemical vapor deposition (MOCVD) and hot filament chemical vapor deposition (HFCVD), and systematic characterization of the mechanical (hardness), tribological (coefficient of friction and surface resistance to wear), chemical (resistance to chemical attach by corrosive liquids and other environments, including body fluids), electrical, and biocompatibility properties of the UNCD films, which make UNCD coatings a multifunctional material for a new generation of external and implantable medical devices and prostheses with order of magnitude superior performance than current metals and polymers used in current medical devices and prostheses.

Retinal detachment is the separation of the sensory retinal tissue from the underlying pigmented epithelium, resulting in partial or total loss of human vision. Worldwide, 1:10,000 people per year suffer retina’s detachment. Current treatments include: 1) repositioning the sensory retina onto the rest of the retinal tissue, sealing the gap via laser heating or external freezing treatment. Current therapies for retina’s reattachment include using a silicone ring or a gas bubble to push the retina back into place. These modalities suffer from drawbacks such as choroidal detachment when using the silicone ring, or postoperative positioning of the patient. These techniques are not optimal for treating retinal detachment in the lower part of the eye. Thus, this chapter describes R&D that demonstrated a revolutionary method for retina reattachment, using a solution containing iron oxide super-paramagnetic nanoparticles (FDA approved) injected in the vitreous space of a rabbit eye and a rare earth magnet implanted on the sclera region outside the eye. Superparamagnetic particles, magnetic only when exposed to a magnetic field, are attracted to the magnet area pushing the retina back into place, then dissolve when the magnet is extracted.The magnet is coated with a biocompatible Ultrananocrystalline Diamond (UNCD) coating.

Pure titanium/titanium alloys are used in orthopedic and dental implants because of previously identified mechanical properties and biocompatibility. However, recent work shoed that these materials suffer from electrochemical corrosion when implanted in the body or the mouth, releasing metallic-oxide particles from oxidized surface, promoting inflammation around the implant, and implant failure. The novel UNCD coating discussed throughout this book exhibits excellent biocompatible and strong resistance to chemical attach by body fluids. This chapter describes the R&D performed to develop UNCD-coated commercial dental implants, hips and knees. The UNCD coating acts as a protective barrier between the implant and the biological environment, preventing release of metallic-oxide particles into the body. Research focused on investigating the osteointegration rate of titanium, UNCD-coated titanium, and UNCD/W-coated titanium implants, using the rat diaphyseal tibia as a model. Optical and SEM pictures showed superior osseointegration and resistance to chemical attach from body fluids, for UNCD-coated metal dental implantsover uncoated ones,

This chapter provides an overview of electromigration in metals, starting from the early studies on bulk metals to the current studies on copper interconnects. Asmicroelectronics technology advances, electromigration becomes an important reliability problem for on-chip interconnects, evolving from the microscale to the nanoscale in copper lines. Key concepts are introduced, including the electron wind force, the Blech short-length effects, and copper damascene interconnects.

In Chapter 8, the statistical nature of electromigration is described. Along with understanding of the basic physical degradation mechanisms, this is an important area of research due to the need for extrapolations from simple test structures to the product level. One has to keep in mind that electromigration testing is usually done on single-link structures. In some instances, a few links are stitched together in a series or parallel fashion, but massive-scale studies with large interconnect arrays have not been implemented yet as a standard testing methodology. Only the application of very large test structures with an extended amount of interconnect links encompassing metal lines and contacts/vias can lead to the detection of “early” or “extrinsic” failures, which are the limiting factor in the extrapolation to product-level interconnect systems. The detection of these early failures in electromigration and the complicated statistical nature of this important reliability phenomenon have been difficult issues to treat for decades in the past. In Chapter 8, an innovative technique utilizing large interconnect arrays in conjunction with the well-known Wheatstone Bridge are discussed, and both Al- and Cu-based interconnect technologies are described.