Electronic devices have seen tremendous improvement since the discovery of electron. A brief history of the progress in microelectronics industry will be presented with emphasis on memory devices and information technology (IT). The limiting factors in the future progress will be discussed, and need for new concepts and devices will be established. Results of memories and logic circuits based on silicon nano-wires as single electron tunneling transistors (SETTs) will also be presented. Microelectronics research at Cavendish laboratory has resulted in a new device named PLEDM. Results are presented with the courtesy of Prof. H. Ahmed. This is shown to be a replacement of DRAM, which is currently the single largest selling electronic component. A new dimension of future microelectronics research will also be discussed.
Nanotechnology, the ability to work at the atomic and molecular level, atom by atom to create materials and structures with new capabilities that will fundamentally change electronics, computers, medicine, biotechnology, and many other industries. The current research in this area is meant to explore the science of nanostructures and new materials, to develop the enabling technology for producing new classes of electronic and biological devices, and to educate the scientists and engineers who will carry this vision forward. This talk is about the prospects of Nanotechnology and the challenges in this emerging field. It is targeted to undergraduate students in Physics, Chemistry, Electrical and Mechanical Engineering. The complexity of the topic was minimal with elementary level. It would span discussion on Carbon Nanotubes, Molecular Electronics, Nano-Electromechanical Systems, Ultrathin (1.7-7nm) oxides and nitrided oxides for CMOS applications and Noise Spectroscopy.
Genome - the complete set of genetic information - determines the nature, form and activities of a living organism. Human genome, present in 23 pairs of chromosomes, consists of 3.2 billion pairs of A,T,C & G repeated over and over again in varying order. Announcement of double helical structure of DNA in 1953, cloning of first gene in 1973 and completion of the human genome sequence in June 2000 are the most outstanding landmarks of all life sciences. A race between the Human Genome Project (HGP), a publicaly funded consortium, and Celera Genomics, a private company, led to completion of human genome sequence much earlier than initially planned. Celera Genomics using a so-called shot gun sequencing strategy coupled with high speed computers using novel software went ahead of the HGP. In spite of the entire sequence known, the complete understanding of chemical structure of all the genes and how they work are decades away. Computer analysis shall be instrumental in locating all the genes within the 23 chromosomes in the human genome, which may turn out to be first step in solving all the mysteries. It will be possible to detect the genetic disorders at an early stage and to design gene therapy procedures accordingly. Pharmaceutical companies are working to create drugs tailored to a patient's genetic profile, boosting effectiveness and drastically reducing side-effects. Current developments have led to new social, philosophical and ethical issues which shall need to be tackled wisely.
Humans are endeavoring to know nature since their origin with the development of structurally complex, conscious mind and later with the development of tools. The tools enable us to explore the depth, in atom, on the one side and the vastness, of universe, on the other extreme. In earth's history, polymerization of simpler organic compounds had formed macromolecules that developed the ability to reproduce its own kind by consuming raw material from the surroundings. Later the demarcation of the replicating matter with the emergence of membrane system permitted to discriminate in various chemicals to let pass or not pass though it. This further led to emergence of electrical and chemical messaging systems. These steps gradually originated life on planet earth. The development in the forms of matter, in time scale, indicates that the key to the changes in the form of matter is the adaptations it acquires to sustain it in the ever-changing surroundings (environment). The process of adaptations in the historical time factor is referred to as evolutionary development in matter. As life developed to more complicated forms, the ability to adapt is enhanced. This has resulted in emergence of a huge variety of the life forms in different environments. The above argument illustrates that sustainability (health) of a form can be understood on the basis of its structure and the performance by the structure for its keep up. The failure in functional capacity, undoubtedly, is due to a change in structural set up and this is referred as failure of sustainability (disease). In the organization of life, from atoms to molecules to macromolecules, to biomolecules, to cell organelles to cells to tissues to organs to an organism and ultimately to community, molecular understanding carries importance in health and disease. In recent times, it has been understood that life actually adjusts its sustainability or failure of the adaptations to survive at its basic organization level i.e. the molecular level. Therefore Human Genome Project, as we understand at present, has far more implication for medicine and biology. The molecular elucidation of basic language, on the basis of structural composition, of life and its expression enables us to provide technological support in sustainability of life. It has been well established, now, that in order to understand health and disease it is necessary to keep in view the molecular basis of the organization of life and its ability/failure to adapt in the changing conditions. The examples of sickle cell genes with resistance to malaria; bone formation diseases related with collagen; respiratory distress syndrome; arteriosclerosis resulting in coronary artery diseases; hirsutism i.e. masculinization in females; obesity etc. may be explained in the above context. It is also an essential attribute of knowledge to secure life in rapidly changing conditions on planet earth due to massive social production activity and to introduce is successfully on other celestial bodies.
Deployable structures are a novel and unique type of engineering structures, which can be packaged for transportation and expanded automatically at the time and site of operation, and in some cases, can be retracted for re-use or other purposes. They retain the functionality of conventional structures and in addition, can undergo large geometric transformations. They are light-weight and very compact when folded. A few deployable structures are in very common use in almost every household umbrellas, folding chairs and tents; however proper research into deployable structures started only three decades ago. In this sense, it is relatively young subject in the long history of structural engineering. Space exploration critically depends on deployable structures, which make possible satellite communication and other space systems. The largest payload volume currently available, provided by NASA, reaches a diameter of 4.6 m and a length of 18.3 m; present and future space structures are more demanding in their volume requirements. Obviously, such structures cannot be delivered into space in their service geometry because launching vehicles are limited in their size. The limitation in payload volumes has urged the widespread use of deployable structures and presents considerable challenge and exciting opportunities for imaginative concepts and ideas. Of interest: The Cambridge University Deployable Structures Laboratory.
Advent of Recombinant DNA Technology has made it possible to detect defective genes and replace them with "good" genes. Consequently the genetic diseases, which result on mutations can now be cured. The first successful gene therapy experient was done on a 9 year old Indian girl Ashanti in 1990 in USA, who was suffering from a fatal immunological disease - SCID, which is caused by a mutation in ADA gene. The scientists introduced the the "good" copy of the gene in her body and were successful in curing her of this fatal disease. This encouraged other researchers and now several methods are being tried to cure genetic diseases. The 21st Century is the era of Gene therapy and keeping in view tremendous advancements made in the Recombinant DNA technology, it is expected that cure for several genetic defects would be available within the next decade.
Some Expert Comments:
- The detection of defective genes and their replacement works quite well in vitro, but not in-vivo.
- There are no cures to genetic disorders based on mutations. I assure you this is incorrect; there has not been a single case of gene therapy curing a genetic disorder. Efforts to transduce normal copies of genes into patients with genetic disorders have been successful to varying degrees, but no cures yet.
- In Ashanta's story, there was no cure - simply incorrect. It was nonetheless a hallmark in biomedical research; it hinted at the promise gene therapy held.
- As far as the claim that genetic therapy may cure several disorders in the next decade, only time will tell. I would not venture to be so prophetic. A few years ago Harold Varmus, then director of the National Institutes of Health, assembled a panel of experts to assess the status of the field of gene therapy. You see, for quite some time many in the field had been feeling that gene therapy was being pushed to the patient's bed prematurely. The panel's conclusion was right on the mark: the field needs much more research at the fundamental levels, such as development of safe, efficient, and specific gene delivery vectors.