Nanotechnology

Scientific basis and major categories

Nanoscience studies phenomena at the nanoscale; nanotechnology applies this knowledge to useful materials and systems. The commonly used 1–100 nanometre range is a working boundary rather than a guarantee of unusual behaviour. Some delivery systems described as nanomedicine exceed 100 nanometres. Nanotechnology is interdisciplinary, connecting physics, chemistry, biology, materials science and engineering.

As particle size decreases, a larger proportion of atoms lies near the surface. This increases opportunities for adsorption and chemical reactions, explaining the usefulness of nanoparticles in catalysts and sensors. Quantum confinement can alter electronic and optical behaviour: semiconductor quantum dots, for example, can emit different colours depending on their size. However, not every nanoscale property is a quantum effect.

Major classes include metal nanoparticles such as gold and silver; metal oxides such as titanium dioxide; carbon-based structures such as nanotubes and graphene; semiconductor quantum dots; and lipid or polymer nanocarriers. Graphene is an atomically thin carbon sheet, while carbon nanotubes are cylindrical structures. Their properties vary with defects, dimensions and processing, so laboratory claims require application-specific validation.

Production, characterisation and translation

Top-down fabrication reduces or patterns bulk materials using methods such as milling, etching and lithography. It is important in electronics but may introduce defects or consume substantial energy. Bottom-up fabrication assembles structures from atoms, molecules or small building blocks through chemical synthesis, self-assembly and deposition. It offers control over composition but requires careful management of impurities, particle growth and aggregation.

Characterisation is essential because identical chemical compositions can behave differently at different particle sizes or surface states. Electron microscopy reveals morphology; atomic force microscopy maps surfaces; diffraction helps identify crystal structure; and light-scattering techniques estimate particle size in dispersions. No single method fully describes a nanomaterial, and measurements in a dry powder may not predict behaviour inside water, soil or the human body.

Translation requires repeatable batches, stable storage, reliable performance and cost-effective scale-up. A promising laboratory filter may fail commercially because nanoparticles detach, membranes foul or regeneration is expensive. Indian policy must therefore support pilot plants, shared testing facilities, metrology, intellectual property management and industry–research partnerships alongside publications and patents.

Strategic and societal applications

In healthcare, nanocarriers can improve the solubility, stability or delivery of certain medicines. Liposomes, polymer particles and lipid nanoparticles can protect therapeutic cargo and modify its distribution. Nanosensors offer sensitive detection of biomarkers, while some nanostructured coatings can reduce microbial growth. Targeted delivery does not mean perfect targeting: biological barriers, immune responses and unintended organ accumulation remain important limitations.

For water treatment, nanostructured adsorbents, membranes and photocatalysts can help remove selected contaminants. High surface area is useful for capturing arsenic or other dissolved substances, but performance depends on water chemistry and competing ions. Treatment systems must prevent nanoparticle release, remain maintainable locally and provide safe disposal of contaminant-laden material. Nanotechnology complements, rather than replaces, sanitation and conventional treatment.

Energy applications include improved battery electrodes, catalysts for hydrogen production and fuel cells, and nanostructured components in solar cells. Shorter ion-diffusion distances can improve charging performance, but greater surface reactivity may also accelerate degradation. Nanocoatings can improve corrosion resistance, while lightweight nanocomposites may reduce transport energy demand.

Agricultural applications include controlled-release nutrient formulations, crop-disease sensors and experimental delivery systems for pesticides. Claims of higher nutrient-use efficiency must be tested across crops, soils and seasons. Electronics uses nanoscale patterning and materials for miniaturisation, sensing and displays. Defence and space applications include lightweight composites, protective coatings and sensitive detectors, but strategic value ultimately depends on reliable domestic manufacturing and supply chains.

India’s institutional and policy landscape

The Department of Science and Technology launched the Nano Science and Technology Initiative in 2001, followed by the Nano Mission in 2007. The Mission was approved with an outlay of ₹1,000 crore for its initial five-year phase. It supported basic research, infrastructure, human-resource development, international collaboration and application-oriented activity. This helped build a wider research base rather than a single-product programme.

Institutions such as the Institute of Nano Science and Technology, Mohali, the Centre for Nano and Soft Matter Sciences, Bengaluru, IITs, IISc and CSIR laboratories contribute to research and training. MeitY-supported nanoelectronics facilities and user-access programmes help researchers work with fabrication and characterisation infrastructure that individual institutions may find difficult to finance.

Regulatory oversight is largely sector-specific rather than based on one comprehensive nanotechnology law. Medical products face applicable drug and medical-device requirements; agricultural inputs, food-related uses and environmental releases involve their respective frameworks. The 2019 Guidelines for Evaluation of Nanopharmaceuticals in India, developed through DBT, ICMR and CDSCO, provide a dedicated evaluation framework. Standards and traceable measurements are crucial for both safety and trade.

Risks, ethics and priorities for responsible innovation

Nanotoxicology examines how nanoscale characteristics influence biological effects. Potential concerns include oxidative stress, inflammation and persistence in tissues or ecosystems. Some particles can cross biological barriers under particular conditions; this cannot be generalised to all nanomaterials. Certain long, rigid and biopersistent fibres require special attention because shape can influence hazard. Workers handling airborne powders may face exposures unlike those of consumers using particles embedded in solid products.

Environmental assessment must examine manufacture, transport, use, recycling and disposal. Nanomaterials may aggregate, dissolve or acquire surface coatings in biological fluids, changing their behaviour. Antimicrobial nanoparticles may affect beneficial organisms, while contaminated filters can transfer pollutants into solid waste. Risk assessment should therefore combine hazard with realistic exposure and examine transformation products, not simply the original material.

India should adopt safe-by-design development, exposure monitoring, suitable workplace controls and lifecycle testing. Independent field trials should precede large-scale public procurement, especially for health and agriculture. Shared pilot facilities and transparent standards can help start-ups cross the research-to-market gap. Public communication must distinguish established products from speculative claims, while ensuring that benefits such as cleaner water and better diagnostics reach underserved communities.

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