The Author is Former Director General of Information Systems and A Special Forces Veteran, Indian Army

Hypersonic, stealth and unmanned systems are dominating conflicts in the 21st century. It is but natural that research in these is advancing at a fast pace. With deepening of the means for intelligence, surveillance and reconnaissance, the need for greater stealth and invisibility is getting more focus.

In January this year, news emerged that China has developed "invisible clothing"; by creating material that could make objects invisible on radar. The metamaterial, named 'Chimera', aims to achieve invisibility across microwave, visible light and infrared (IR) frequencies. The research capitalises on the rapid advancements in metamaterials known for their unique ability to bend electromagnetic waves. The name Chimera has been drawn from the composition of different legendary creatures, amalgamating the chameleon's colour adaptation, the glass frog's transparency, and the bearded dragon's thermal regulation.

India's IIT-K has developed Anālakṣhya, a meta-material system for enhanced stealth in combat systems, with significant implications for defence and national security.

Promising that Chimera will be imperceptible across a spectrum of microwave, visible light and infrared frequencies, the study published in China's National Academy of Science showcases a bionic-based approach, addressing the limitations of current camouflage technologies which usually falter across varying terrain. Xu Zhaohua, the lead researcher and author of the study from Jilin University, remarking on the versatility of the Chimera metamaterial, stated, "It was intriguing that that suitable working states of the Chimera meta surface can be found to match all the five terrains over the whole frequency range of interests." The study mentions the researchers stating, "our work transitions camouflage technologies from the constrained scenario to ever-changing terrains and constitutes a big advance towards new-generation reconfigurable electromagnetics that can change circuit topologies."

The design of Chimera mirrors the chameleon's ability to harmonize its microwave reflection properties with diverse landscapes. It also draws from the glass frog, known for its near-invisibility during sleep by concealing most of its blood in the liver; by embedding its circuitry between layers of PET plastic and quartz glass to achieve a similar level of optical transparency. The legendary bearded dragon is unique in thermal regulation. By adopting a mechanically-driven design, the Chimera's thermal footprint is minimised to a negligible 3.1 degree Celsius (5.6-degree Fahrenheit), making it virtually invisible.

France has offered advanced pump-jet propulsion technology for India's submarine projects, marking a leap in underwater stealth capabilities.

How much the Chimera concept has implemented by China is not known but potential applications of this technology are immense both in the military and civil fields. In military operations, it could contribute towards tactical and strategic advantages, spying and special operations and the like. A Chinese national was recently caught trying to enter US President-elect Mar-a-Lago home in Florida. But what if he was wearing a Chimera invisible cloak?

On November 26, 2024, the Indian Institute of Technology Kanpur (IIT-K) announced a breakthrough in stealth technology, which would make combat systems like tanks and fighter aircraft "invisible" or "near-invisible" to enemy radar. Designated a 'meta-material surface cloaking system' (MSCS), this has been named "Anālakṣhya".

Stealth systems avoid detection by enemy radar through two devices: first, by engineering its external surface with small jagged panels that scatter radar waves, rather than large flat surfaces that reflect back radar waves to be detected by enemy radar antennae; second, a device that renders battlefield systems such as stealth fighters hard to detect is their surface composition.

This textile-based, broadband, Anālakṣhya meta-material microwave absorber offers near-perfect wave absorption across a broad spectrum, significantly enhancing stealth capabilities against SAR imaging. It sets a new benchmark in multispectral stealth capabilities, offering transformative applications in defence, national security, and specialised industries. The Anālakṣhya MSCS not only offers wave absorption across a broad spectrum, it also provides effective protection from missiles that use radar guidance.

Anti-stealth radar advancements from China and Russia present evolving challenges to stealth technologies like F-22 and F-35 jets.

Naturally, Anālakṣhya is of major interest to the Defence Research and Development Organisation (DRDO), especially related to the development of the Advanced Medium Combat Aircraft (AMCA) stealth fighter; making it near-invisible to enemy radars. The technology has undergone extensive laboratory and field testing between 2019 and 2024, proving its efficacy across diverse conditions.

High-technology cooperation between indigenous defence industry and academia has begun yielding results. The Anālakṣhya system is currently under acquisition by the Indian Armed Forces, indicating its strategic importance to national security. According to a statement, 90 per cent of the Anālakṣhya MSCS is sourced indigenously. In a significant move towards industrial production, the technology has been licensed to a private company 'Meta Tattva Systems', which will oversee its manufacturing and deployment.

A recent news is that France has offered advanced pumpjet propulsion technology for India's Project 66 and Project 77, which is the initiative to acquire nuclear-powered attack submarines (SSNs), enhancing stealth, manoeuvrability, and operational effectiveness, strengthening India's underwater capabilities; for making India Navy's submarines almost invisible in the Indian Ocean Region (IOR).

India's collaborative approach in developing indigenous stealth technologies highlights a strategic focus on self-reliance and innovation.

The pump-jet propulsion technology, a sophisticated alternative to traditional propeller systems, is already operational in the French Barracuda-class submarines. The technology significantly decreases the acoustic signature of submarines, allowing for quieter operations and improved stealth capabilities. Such capability would be a major advantage for the Indian Navy in underwater warfare. Stealth is of extreme importance to submarines operating in hostile waters. This cutting-edge tech will give the Navy an added edge while navigating complex waters.

The French willingness to offer this advanced technology to India demonstrates the growing defence ties between the two countries. At the same time, a report titled 'Australia's Future Submarine: Getting this Key Capability Right' states, "In a comparison between two otherwise identical submarines, the one with the pump jet will always have a lower dived endurance, a lower dived range, a worse indiscretion ratio, a lower overall endurance, and a lower overall range, than the one with a propeller. This will confer a substantial tactical and strategic advantage on the conventionally-propelled submarine in a very broad range of operational scenarios." Adoption of the pump-jet propulsion technology through co-design, co-development, and co-production of military hardware will enhance the Indian Navy's operational effectiveness of its submarine fleet.

China's anti-stealth radar systems deployed along its coastline and on naval ships are reportedly capable of detecting US F-22 and F-35 fighter jets at considerable distances. A recent news report says a new coating can make China's stealth aircraft invisible to anti-stealth radar, Russia has also offered its Buk-M3 anti-stealth radar to India which can target the F-35 and F-22 fighter jets, Stealth and invisibility are no doubt assets but both will progress together with improvements in detection systems. They can hardly be expected to be completely foolproof, as is the case with cybersecurity.