IIT Madras Researchers Develop Materials and Micro Device processing technologies for Underwater Acoustic Sensors

CHENNAI: Indian Institute of Technology Madras (IIT Madras) Researchers partnered with Defence Research and Development Organisation (DRDO) Scientists to develop cutting-edge sensor technology for underwater communications, which will be advantageous to defence applications, especially in the Navy. 

The indigenous development of this technology enables the nation to fabricate the devices at a relatively lower cost than the internationally-available foundries where the cost of fabrication is high and the number of foundries is also limited. 

This is a major development on the eve of National Technology Day (11^th May 2023) that has attained a high Technology Readiness Level (TRL), a measurement used to assess the maturity level of a particular technology. The National Technology Day is celebrated on 11th May annually to celebrate the achievements of scientists, engineers and researchers

The ‘Piezoelectric MEMS technology’ is required to develop high-performance thin films and convert ‘piezo thin film’ into state-of-the-art futuristic Naval Sensors and devices for underwater applications. The Piezo Thin Films are one of the vital components of piezo MEMS devices and are considered for acoustics and vibration-sensing applications.

IIT Madras Researchers led by Prof. Amitava Das Gupta and Prof. Boby George along with Dr. E. Varadarajan, Scientist, and Dr. V. Natarajan, Senior Scientist of DRDO at the DRDO Industry Academia – Ramanujan Centre of Excellence (DIA-RCoE), IIT Madras. They worked multiple partners for the indigenous development of a piezo MEMS (Micro Electro Mechanical System) process technology to make ‘Thin film membrane based Piezo MEMS Acoustic sensors.’

The establishment of cutting-edge piezo MEMS technology enables India to push the boundaries of defence competencies and allows the nation to execute the strategic operations of critical applications. The large area piezo thin films and MEMS process technology will support the ongoing/ futuristic technologies for the Next-Generation SONAR programme of DRDO for the Indian Navy

Congratulating the Researchers and Scientists on this project, Prof. Manu Santhanam, Dean (Industrial Consultancy and Sponsored Research), IIT Madras, said, “The outcome of the DRDO and Academia collaboration has resulted in the development of this novel technology which will be vital for the Indian Navy.”

The Research was led by DRDO Industry Academia – Ramanujan Centre of Excellence (DIA-RCoE), IIT Madras. The DRDO Laboratories involved in this project include the Naval Physical and Oceanographic Laboratory, (NPOL), DRDO, Kochi, and Naval Science and Technological Laboratory (NSTL), DRDO, Visakhapatnam. Other collaborators include the Armament Research and Development Establishment (ARDE), Pune, Vellore Institute of Technology (VIT) Chennai and Indian Institute of Science (IISc) Bengaluru. 

Speaking about this project, Dr. O.R. Nandagopan, Director, DRDO Industry Academia- Ramanujan Centre of Excellence’ (DIA-RCoE), IIT Madras, said, “This technology is matured enough to convert it as a system with the support of Indian Industry.  This technology will be a disruptive technology in this domain and our country achieved ‘Aatma Nirbhar Bharat’ in underwater materials and micro device processing technology.”

Across the globe, several research groups and Defence laboratories in the U.S., Europe, Korea, Japan and China are involved in the development of technologies. Internationally, several piezo MEMS foundries are making various piezo MEMS devices for both defence and civilian applications. Currently, the piezo thin film-based piezoelectric device market is worth around US$ 5 billion US and is estimated to grow at a Compound Annual Growth Rate (CAGR) of 12 % in the next 3 to 4 years.

Further, Prof. Amitava Das Gupta, Department of Electrical Engineering, IIT Madras, added, “The facility for the fabrication is established at IIT Madras and also at DRDO Industry Academia – Ramanujan Centre of Excellence.  It is a great achievement together by IIT Madras and DRDO.”

The indigenous development of Piezo MEMS technology connects the technology gaps leading to the development of piezo MEMS acoustic devices for underwater applications. Large dimension (100 mm dia) Piezoelectric thin films were fabricated by both RF sputtering and Sol-Gel technique with good uniformity and higher piezoelectric properties. 

Dr. Varadarajan, Scientist, DRDO highlighted that the main challenge in the Piezo MEMS process technology is the need for high reliability and durability in harsh underwater environment,  high pressure and corrosive nature of seawater.

The piezo MEMS process recipe has been successfully developed jointly with DRDO team for the complete fabrication of an acoustic sensor, without degrading the functionality of the piezo thin film. The fabricated PZT thin film-based acoustic sensor exhibits higher performance than the conventional PVDF-based acoustic sensor. This cutting-edge sensor technology allows the researchers to fabricate high-performance piezo MEMS acoustic devices, which will be advantageous to defence applications.