Recent Patents on Nanotechnology - Volume 4, Issue 2, 2010

Chemo-mechanical polishing (CMP) has been a common method to produce nano-scale surface finish of brittle wafers. This paper provides a relatively comprehensive review on the CMP of silicon, silicon carbide and sapphire including both patents and papers. The discussion includes the limitations and further research directions of the CMP technology, the material removal mechanisms, and the control and optimization of the CMP for brittle wafers. The paper concluded that the usage of mix- or coated- abrasives may improve the CMP in terms of less subsurface damage and higher material removal rate.

The supercritical state provides an energetic environment in which high-aspect-ratio or active surface structures can be reacted, swelled, cleaned, or coated. Due to both low viscosity and low interfacial tension, reagent, solvent, rinsing and drying media of supercritical fluids can be efficiently delivered into the nanointerstices of a substrate. This article summarizes recent patents in the field of using supercritical fluids in nanolithographic processing methods such as drying, removal of lithographic resist, and formation of hybrid structures. Some of our recent efforts on restoring the collapsed on-chip nanotube arrays, and synthesizing zeolite-polymer hybrid membrane materials are exemplified as applications of supercritical fluids. Introducing supercritical effects may guide sustainable technologies for the development of green processes.

Protein-imprinted materials have drawn great attention nowadays for their promising applications in biotechnology and biomedical engineering. Despite the success of molecular imprinting technique of small molecules in chemical and biomedical industry, imprinting of large molecules especially biomacromolecules remains a challenge. In recent years, however, a number of significant protein imprints have been reported, some of which may have great potential in applications for chromatography and biosensors. In this article, we review current development and patents on various protein imprinting approaches and materials. The advantages and disadvantages of the methods are discussed, and the trends are also highlighted.

As the vital part of lithium ion batteries, conductive additives play important roles on the electrochemical performance of lithium ion batteries. They construct a conductive percolation network to increase and keep the electronic conductivity of electrode, enabling it charge and discharge faster. In addition, conductive additives absorb and retain electrolyte, allowing an intimate contact between the lithium ions and active materials. Carbon nanomaterials are carbon black, Super P, acetylene black, carbon nanofibers, and carbon naotubes, which all have superior properties such as low weight, high chemical inertia and high specific surface area. They are the ideal conductive additives for lithium ion batteries. This review will discuss some registered patents and relevant papers about the carbon nanomaterials that are used as conductive additives in cathode or anode to improve the electrochemical performance of lithium ion batteries.

Magnetic nanoparticles have been proposed for biomedical applications for several years. Various research groups worldwide have focused on improving their synthesis, their characterization techniques and the specific tailoring of their properties. Yet, it is the recent, impressive advances in nanotechnology and biotechnology which caused the breakthrough in their successful application in biomedicine. This paper aims at reviewing some current biomedical applications of magnetic nanoparticles as well as some recent patents in this field. Special emphasis is placed on i) hyperthermia, ii) therapeutics iii) diagnostics. Future prospects are also discussed.

Despite aggressive multimodal strategies, the prognosis in patients affected by primary brain tumors is still very unfavorable. Glial tumors seem to be able to create a favorable environment for the invasion of neoplastic cells into the cerebral parenchyma when they interact with the extracellular matrix via cell surface receptors. The major problem in drug delivery into the brain is due to the presence of the blood brain barrier which limits drug penetration. Nanotechnology involves the design, synthesis and characterization of materials that have a functional organization at least in one dimension on the nanometer scale. Nanoengineered devices in medical applications are designed to interface and interact with cells and tissues at the molecular level. Nanoparticle systems can represent ideal devices for delivery of specific compounds to brain tumors, across the blood brain barrier. In this brief review, we report the results of studies related to the emerging novel applications of nanoparticle systems in diagnosis and treatment of primary brain tumors, and also the patents of studies that adopt nanoparticle systems as drug delivery carriers in brain tumor diagnosis and therapy.

Hematopoietic stem cell transplantation has been applied as a standard procedure of treatment for hematological disorders like multiple myeloma and leukemia for several decades. Various sources of stem cells like bone marrow, peripheral blood and umbilical cord blood are used for the transplantation. Among these umbilical cord blood is currently preferred due to the primitiveness of the derived stem cells and minimal possibilities of graft versus host disease or development of graft induced tumors. One of the problems for these sources is the procurement of sufficient number of donor stem cells. Inadequate number of cells may lead to delayed recovery and decrease survivability of the patient. Thus to overcome the limitation of stem cell number, development of an ex-vivo expansion technology is critically important. The recent emerging technology using nanofiber in combination with growth factors has made a significant improvement to the field of regenerative medicine and a couple of patents have been filed. In this review, we will focus on factors regulating hematopoietic stem cell self-renewal and expansion emphasizing on nanofiber as a supporting matrix.

The patents annotated in this section have been selected from various patent databases. These recent patents are relevant to the articles published in this journal issue, categorized by different nanotechnology methods, processes and techniques involved.