Annual Report 2006-2007

Scientific Research

Nano Science and Technology Initiative (NSTI)

Under its Nano Science & Technology Initiative (NSTI), the Department continued its support for R&D in potential and challenging areas of Nano Science & Technology. It extended support to scientists for their individual projects, setting up of core groups and units around outstanding scientists and centres for Nano Technology.

In addition to individual research projects, the cluster of 11 Units on Nano Science established at various locations were further strengthened through the creation of the following Centres for Nano Technology during the year:

A. Indian Institute of Science, Bangalore: The Centre would focus at the development of nanodevices based on thin film technologies (self-assembly, LB films), synthesis of molecules (surfactants used for preparing various assemblies) and polymers. Various physical and chemical characterization techniques (microscopy, spectroscopy and diffraction - based techniques) of nanomaterials would be employed. The centre would also focus on technology development in the areas of nanocomposites and nanobiosensors.
Specifically:

1. The centre would develop biosensors capable of detecting carbohydrates mediated pathogenic infections.

2. In the area of nanodevice, the main focus would be on development of high density nonvolatile memory elements for random access memories and nanotube based integrated circuits and devices.

3. In the area of nanocomposites, energy storage devices with large capacity e.g. super-capacitors, would be fabricated using CVD-produced manganese oxide nanocomposite coatings.

B. Indian Institute of Technology Bombay, Mumbai: This Centre would acquire state-of-the-art equipments for carrying out research in the broad areas of Nanobiotechnology, Nanoelectronics and Nanomaterials.

A few selected research activities that would be undertaken in this centre are:

1. Engineered/Hybrid Nanomaterials for Healthcare, Scientific and Engineering Applications: The goal of this work would be to develop novel hybrid materials for clinical and engineering applications.

This would includea.

a. Magnetic nanoparticles for hyperthermia treatment of cancer and MRI contrast agent

b. Delivery of drugs: liposome based, magnetic nanoparticles attached with drugs for targeted delivery

c. Core-shell hybrid nanomaterials, ultrahydrophobic nanomaterials, sunscreen nanomaterials, quantum spin chains, polymer nanocomposites, Ni & Co nanorods and nanowires etc.

2. Nanobiotechnology for Therapeutic Applications: Several investigations in the broad area of nanobiotechnology such as cell biology, genetic engineering, protein chemistry, computational biology including bioinformatics etc. with therapeutic applications are planned. The team shall address the following themes:-

a. Novel surfactants nanoparticles for respiratory disease

b. Cellular and molecular engineering

c. Nanocomposites for dental and orthodontics use

d. Micro-devices for cardiac use

e. Nanoparticles as biocatalysts

f. Controlled drug delivery systems

3. Nanoelectronics for Healthcare Monitoring and Diagnosis: This would look into the following:-

a. Nano-device fabrication for molecular electronics

b. Nanosystems for health care and environmental monitoring

4. Conducting Polymer Based Sensors: The focus would be on:-

a. Nano conducting polymers as building blocks for IC

b. Actuators as sensors, valves and pumps

c. Organic LEDs

C. National Centre for Biological Sciences (TIFR), Bangalore: This Centre would focus on the study of the nano-scale in biology. The main thrust of the Centre would be to develop versatile platforms to allow modular implementation of high-content, high-throughput screening devices based on nanoscale biosensors for a variety of cellular processes. These devices would be realized by achieving the three major scientific objectives stated below:

a) High throughput and high content RNAi screens for studying nanoscale cellular processes

b) Understanding the functional roles of critical cellular components (cytoskeleton and chromatin assembly) using nanoparticle assisted targeting and localized laser ablation within single living cells

c) Development of biosensors using unusual nucleic acid structures and their applications to probe cellular processes

D. SN Bose National Centre for Basic Sciences, Kolkata: The Centre would develop technology platforms, devices and products in MEMS and NEMS. Specifically, they would focus oni.

Development of technology and technique for sub-micron MEMS/NEMS to fabricate Si wafer arrays of Si/Si3N4 structures.

ii. Development of technology to grow nanowires and nanoparticles or arrays of them of particular size at a predetermined location on the MEMS/NEMS

iii. Development of technology to attach nanoparticles to fabrics and natural fibres and related surface treatments

iv. Development of technology for wide area growth of grain size and controlled nanostructured films and multilayers of functional oxides

E. Indian Institute of Technology, Kanpur: The Centre would develop prototyping tools in the area of printable electronics and nano-patterning for novel manufacturing paradigms. It would also focus on development of technologies and prototype devices using organic and polymer based nanomaterials and nanostructures. The broad objectives are:

• Setting up enabling facilities for nanotechnology based device development with specific initial focus on printable electronics using soft materials such as molecular solids and polymers and their heterostructures with inorganic systems;
• Encouraging researchers in nanotechnology to harness the capabilities in nano-patterning and structures in soft materials for applications in fluidics, sensors, and manufacturing.
• Providing facilities and systems so as to enable demonstration of prototype devices such as organic semiconductor based RFID tags.

F. Indian Association for the Cultivation of Science, Kolkata: This Centre would focus on design and synthesis of materials suitable for applications in photovoltaics and sensors. Humidity and other gas sensors employing nanocomposites based on metal-metal oxide interfaces would be developed. In addition, they would look at design and synthesis of core-shell and quantum well structures based on group II-VI semiconductors with high efficiency for photovoltaic applications.

Several interesting results were reported from ongoing projects.

A remarkable discovery of induction of electrical signals (voltage / current) in a sample of single-walled carbon nanotube bundles along the direction of flow of various liquids and gases over it was reported in a project being implemented the at Indian Institute of Science. The electrical response generated by the flow of liquids is found to be logarithmic in the flow speed over a wide range. In contrast, voltage generated by the flow of gas is quadratically dependent on the gas flow velocity. For the liquid, the Coulombic interaction between the ions in the liquid and the charge carriers in the nanotube plays a key role while electrical signal generation due to gas flow is due to interplay of Bernoulli's principle and Seebeck effect.
In another project progressing at Indian Institute of Technology Guwahati, a new and interesting method of fabrication of surface tension confined two-dimentional microfluidic devices on glass was reported. The simplicity and low fabrication cost are the strengths of this method. By suitably printing hydrophobic lines on hydrophilic surface, a working device could be made. Some well known chemical reactions using a few hundred nanolitre volumes of reagents were demonstrated in these microfluidic devices. These results promise applications in the fields of pharmaceutical industry, drug delivery, automated, miniaturized, intelligent pneumatic systems, inkjet printing etc.

Understanding of negative differential resistance (NDR) in nanoscale systems in a project at the Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore led to some interesting results. The effects of electron-phonon coupling on current-voltage characteristics of a 1-D molecular wire with odd number of atoms were investigated. In the presence of strong electron-lattice coupling, the investigators found that there were regions of NDR at some critical bias, due to the degeneracy in the energies of the frontier molecular orbitals. The presence of the applied bias and the electron-lattice coupling results in the delocalization of these low-lying molecular states leading to the NDR behavior.

Significant steps were taken during the year to elevate the Nano Science & Technology Programme of DST to the level of a mission-mode programme.

The broad discipline wise details of the achievements are as follows: