Recent Patents on Nanotechnology

ISSN: 1872-2105

Recent Patents on Nanotechnology
Volume 2, Number 1, January 2008

Contents


Electrospinning for Bone Tissue Engineering Pp. 1-7
Koushik Ramachandran and Pelagia-Irene Gouma
[Abstract]


Chemical Methodologies for Preparation of Micron and Nanometer Scale Ferrites Pp. 8-18
Prita Pant, Sundararaman Bhuvaneswari and Narendra Nath Ghosh
[Abstract]


Interrogating Single Molecules Pp. 19-24
Lin Cong and Alexander D. Wissner-Gross
[Abstract]


Large-Scale Carbon Nanotube Synthesis Pp. 25-40
Kiern J. MacKenzie, Oscar M. Dunens, Chee H. See, and Andrew T. Harris
[Abstract]


Nanostructured p-Type Semiconducting Transparent Oxides: Promising Materials for Nano-Active Devices and the Emerging Field of Transparent Nanoelectronics Pp. 41-68
Arghya Banerjee and Kalyan K. Chattopadhyay
[Abstract]


Patent Selections Pp. 69-71




Abstracts


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Electrospinning for Bone Tissue Engineering
Koushik Ramachandran and Pelagia-Irene Gouma

Bone tissue engineering is a field of significant research interest owing to the large number of bone defects and the limitations in the present techniques to effectively reconstitute the defects. Cell-based bone graft technique has shown promise in overcoming the limitations of the other bone graft techniques currently used. However the success of this technique is dependent on the choice of appropriate material and processing route. Biodegradability, Osteoinductivity, High porosity with interconnected pores and mechanical stability are some of the important requirements for a tissue engineering scaffold. Several techniques have been demonstrated to fabricate bioscaffolds. However, most of these methods lack the capability to produce three dimensional scaffolds with complex pore structures in a single step. Electrospinning, invented to prepare polymeric threads, has recently emerged as a leading technique for fabricating bioscaffolds for bone tissue engineering. The process has the versatility to produce scaffolds with required morphology and porosity to suit the needs of tissue engineering. This paper reviews some of the recent patents issued in the field of electrospinning and bone tissue engineering.


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Chemical Methodologies for Preparation of Micron and Nanometer Scale Ferrites
Prita Pant, Sundararaman Bhuvaneswari and Narendra Nath Ghosh

Ferrites, with wide range of chemical compositions, have been studied extensively over the years as they have a plethora of applications such as magnetic read/write heads, transformer cores, antennas, microwave absorbers, deflecting yoke, high frequency transformers, catalysis, pigments etc. Particles of submicron size have attracted the attention of scientists and technologists in different fields because they exhibit many unique physical properties as compared to those of bulk materials and are in great demand. Traditional high temperature solid-state method for preparation of ferrites is associated with several limitations. The quest for synthesis of ultrafine ferrite materials has led to the development of various preparative methods. Several patents disclose different wet chemical techniques namely sol-gel, coprecipitation, hydrothermal, combustion, spray pyrolysis etc for preparation of variety of ferrites for wide range of applications. In this mini-review, several patented chemical methods have been discussed critically with specific examples along with the effect of synthetic routes on particle size formation. Applications of ferrite powders with different compositions prepared by the above mentioned patented methods have also been discussed in this review.


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Interrogating Single Molecules
Lin Cong and Alexander D. Wissner-Gross

The development of nanotechnology relies heavily on the ability to observe and probe at molecular scales. Thus, breakthroughs in instrumentation and techniques play a significant role in the advancement in nanoscience. In this article, we survey recent developments in observing, trapping, and probing single molecules in solution. We give particular attention to patents that cover enabling instrumentation in each of these related areas including, respectively, fluorescence imaging, optical tweezers, and anti-Brownian traps. We conclude by highlighting a broad trend in the literature and patent base from observation toward active interrogation of single molecules in solution.


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Large-Scale Carbon Nanotube Synthesis
Kiern J. MacKenzie, Oscar M. Dunens, Chee H. See, and Andrew T. Harris

Carbon nanotubes (CNTs) are a form of crystalline carbon with extraordinary chemical, physical, electrical and mechanical properties, making them potentially valuable in a broad range of applications. These properties have resulted in an unprecedented level of interest in the development of techniques to manufacture CNTs, and consequently a raft of competing patents have been issued, with universities and commercial entities alike looking to obtain patent protection for their inventions. In this paper we review relevant aspects of international patent law, summarize CNT definitions and discuss patent irregularities, and discuss the implications of the widening gap between nanotechnology practice and the underlying patent law. This is followed by a review of the chemical vapour deposition technique of CNT synthesis, in particular using a fluidised bed, identified as the most promising method to date for the large-scale, low cost production of CNTs. We further examine the carbon nanotube patent space, focusing primarily on patents for CNTs produced via CVD and FBCVD techniques. This patent space is both convoluted and uncertain, and it appears likely that some form of litigation will ensue in future to ultimately determine intellectual property ownership in various regions. We also discuss the likely effect of this ‘patent thicket’ on the commercialisation of large-scale CNT synthesis processes.


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Nanostructured p-Type Semiconducting Transparent Oxides: Promising Materials for Nano-Active Devices and the Emerging Field of Transparent Nanoelectronics
Arghya Banerjee and Kalyan K. Chattopadhyay

Transparent conducting oxides (TCO) with p-type semiconductivity have recently gained renewed interest for the fabrication of all-oxide transparent junctions, having potential applications in the emerging field of ‘Transparent’ or ‘Invisible Electronics’. This kind of transparent junctions can be used as a “functional” window, which will transmit visible portion of solar radiation, but generates electricity by the absorption of the UV part. Therefore, these devices can be used as UV shield as well as UV cells. In this report, a brief review on the research activities on various p-TCO materials is furnished along-with the fabrication of different transparent p-n homojunction, heterojunction and field-effect transistors. Also the reason behind the difficulties in obtaining p-TCO materials and possible solutions are discussed in details. Considerable attention is given in describing the various patent generations on the field of p-TCO materials as well as transparent p-n junction diodes and light emitting devices. Also, most importantly, a detailed review and patenting activities on the nanocrystalline p-TCO materials and transparent nano-active device fabrication are furnished with considerable attention. And finally, a systematic description on the fabrication and characterization of nanocrystalline, p-type transparent conducting CuAlO₂ thin film, deposited by cost-effective low-temperature DC sputtering technique, by our group, is furnished in details. These p-TCO micro/nano-materials have wide range of applications in the field of optoelectronics, nanoelectronics, space sciences, field-emission displays, thermoelectric converters and sensing devices.