Over the past half century, rapid progress has been made in laser-based medical diagnosis and treatment as well as in laser-based medical device fabrication. Lasers have unique capabilities for coating, machining, melting, polymerizing, sintering, and welding materials that are used in implantable and transdermal medical devices. In this review, academic and industrial developments involving laser processing of materials for dental, orthopedic, neural, ophthalmic, cardiovascular, and transdermal applications are described. In addition, laser processing of nanoscale materials for medical applications is discussed. Finally, challenges associated with commercialization of laser biomaterials are considered. Due to the unique capabilities provided by laser-based processes, it is anticipated that the use of laser biomaterials in implantable and transdermal medical devices will markedly increase over the coming years.

A new expanding cavity model (ECM) for describing conical indentation of elastic-ideally plastic material is developed. For the proposed ECM, it is assumed that the volume of material displaced by the indenter is equal to the volume loss, due to elastic deformation, in the material and depends on the pile-up or sink-in. It was shown that the proposed ECM matches very well numerical data in the final portion of the transition regime for which the contact pressure lies between approximately 2.5Y and 3Y. For material of large E/Y ratio, the new ECM also provides results which are very close to the numerical data in the plastic-similarity regime (regime in which Cf = 3). For material of smaller E/Y ratio, the proposed ECM gives better results than the Johnson’s ECM because pile-up or sink-in is taken into account.

Laser-assisted bioprinting is one among several technologies that are being developed in the recent and growing field of bioprinting. Bioprinting is defined as the use of computer-aided transfer processes for patterning and assembling living and non-living materials with a prescribed 2D or 3D organization in order to produce bio-engineered structures serving in regenerative medicine, pharmacology, and basic cell biology studies. We describe the physical parameters that need to be tuned for laser-assisted bioprinting of materials and cells, with high throughput and controlled printing resolution. We present its applications for printing cells and tissue-relevant biomaterials, both in vitro and in vivo. Finally, we discuss how this technique may help in reproducing the local cell micro-environment and dealing with tissue complexity and heterogeneity for fabricating functional tissue-engineered 3D constructs.

Rapid prototyping (RP) technologies, which are based on computer-aided design and computer-aided manufacturing, are widely employed in traditional industries. They are capable of achieving extensive and detailed control over the architecture of objects to be formed and therefore are increasingly used in the biomedical engineering field. Selective laser sintering (SLS), a versatile RP technique, uses a laser beam to selectively sinter powdered materials to form three-dimensional objects according to designs that can be based on data obtained from computer-based medical imaging technologies. In this article relating to biomedical applications, the principle, materials, machine modification, and parameter optimization for SLS are reviewed. Biomedical applications of SLS, especially in the fabrication of tissue engineering scaffolds and drug/biomolecule delivery vehicles, are presented and discussed. SLS exhibits great potential for many applications in biomedical engineering.

Since the emergence of tissue engineering (TE), numerous researchers, particularly in the areas of materials, biological science, and engineering, have aimed to provide viable substitutes for the repair and regeneration of musculoskeletal and organ tissues. Bone TE has been extensively explored to mimic the anatomical geometry of bone with varied pore size distribution and varying mechanical properties in a radial direction (a functional gradient). This TE approach was explored to promote faster functional recovery of defective bones due to congenital, traumatic, or degenerative reasons. The present study integrated an appropriate additive manufacturing or rapid prototyping technique with automated computer-aided design models. This process was applied to the manufacture of a functionally graded scaffold (FGS). The FGS system takes into consideration both microscale anatomical geometries and mechanical properties of the native bone via an established porosity-stiffness relationship. Experimental verification of the FGS model was carried out by the fabrication of a femur bone segment using a selective laser sintering system. The physical femur model demonstrated good replication of the FGS structure that was generated. Future work aims to implement the FGS system for other musculoskeletal and organ tissues and integrate the current work with the authors’ in-house developed “computer aided system for tissue scaffolds” or CASTS system.

Advances in nanoscience and nanotechnology critically depend on the development of nanostructures whose properties are controlled during synthesis. We focus on this critical concept using semiconductor nanowires, which provide the capability through design and rational synthesis to realize unprecedented structural and functional complexity in building blocks as a platform material. First, a brief review of the synthesis of complex modulated nanowires in which rational design and synthesis can be used to precisely control composition, structure, and, most recently, structural topology is discussed. Second, the unique functional characteristics emerging from our exquisite control of nanowire materials are illustrated using several selected examples from nanoelectronics and nano-enabled energy. Finally, the remarkable power of nanowire building blocks is further highlighted through their capability to create unprecedented, active electronic interfaces with biological systems. Recent work pushing the limits of both multiplexed extracellular recording at the single-cell level and the first examples of intracellular recording is described, as well as the prospects for truly blurring the distinction between nonliving nanoelectronic and living biological systems.

This article lays the foundation for the development of microwave plasma chemical vapor deposition process conditions for synthesizing multilayered microcrystalline and nanocrystalline diamond (MCD and NCD) thin films. The effects of gas composition and the diamond seeding medium are correlated with the film morphology and diamond phase purity. Results of process optimization experiments using single-layer diamond deposition indicate that for high gas-phase Ar content (≥90%) the film quality improves with reduced Ar content and with increasing thickness reaching a plateau above a thickness of ∼2 μm. Multilayer diamond deposition experiments with two different seeding media (25 nm and 1 μm) clearly show that it is feasible to selectively synthesize alternating MCD (60% Ar) and NCD (95% Ar) layers with good control of film quality and morphology, thereby setting the stage for development of multilayered diamond thin films with tailored properties for thermal management applications.

Protocols are developed to assess viscoelastic moduli from unloading slopes in Berkovich nanoindentation across four orders of magnitude in time scale (0.01–100 s unloading time). Measured viscoelastic moduli of glassy polymers poly(methyl methacrylate), polystyrene, and polycarbonate follow the same trends with frequency (1/unloading time) as viscoelastic moduli generated from dynamic mechanical analysis and broadband viscoelastic spectroscopy but are 18–50% higher. Included in the developed protocols is an experimental method based on measured indent area to remove from consideration indents for which viscoplastic deformation takes place during unloading. Ancillary measurements of indent area and depth reveal no detectable (∼1%) change in area between 200 s and 4.9 days following removal of indenter.

Micro- and nanostructures are found widely in nature and are important for the development and maintenance of organisms. Fabricated structures of dimensions corresponding to native biological structures may be obtained by methods such as laser-based fabrication and are of special relevance to applications in biology and medicine, as they impact cellular behavior. In this review, we will examine how fabricated structures of a particular length scale interact with natural structures of corresponding dimensions to produce the designed response, thus giving readers a primer on how laser-based fabrication may be fruitfully applied to biomedicine. Lasers have been used to fabricate nanopores for a variety of applications at the molecular level, such as the analysis of DNA. At the subcellular level, microstructures such as elastic beams fabricated by laser direct writing have been used to adhere and interact with cells. In the area of tissue engineering, an important application of micro- and nanostructures is related to their ability to control intercellular interactions. The fabricated structures facilitate the positioning of cells with respect to each other, so as to simulate the complexity of native tissues. Focused laser sources have also been used to create channels modified with functionalities to help guide cell migration.