Indian Scientists Develop Wearable Ammonia Gas Sensor

Key Facts

• Development Date: 14 July 2026
• Developed by: Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru, an autonomous institute under the Department of Science and Technology (DST)
• Research Team Leader: Prof. Angappane Subramanian
• Other Team Members: Dr. Vishnu G. Nath, Ankur Verma, Abhijit Paul, Dr. Subash Cherumannil Karumuthil
• Detection Limit: 319 parts per billion (ppb) of ammonia
• Technology: Hybrid vanadium oxide-vanadium sulfide (VOx/VS2) heterostructure sensor
• Operating Conditions: Room temperature (20–25°C)
• Form Factors: Flexible sensors fabricated on polymer, paper, and textile substrates enabling wearable applications including smart bands and electronic textiles
• Functionality: Threshold-triggered monitoring system that classifies ammonia levels into safe, warning, and danger zones with real-time alerts
• Performance: Selective sensing against common interfering gases, stable operation over repetitive sensing cycles, and long-term reliability beyond ten weeks

Background & Context

Ammonia (NH3) is a colourless gas widely used in fertilizers, refrigeration, chemical manufacturing, and various industrial processes. Exposure to elevated ammonia concentrations can adversely affect the eyes, skin, and respiratory system, making its detection crucial for occupational and environmental safety.

Conventional ammonia gas sensors often require elevated temperatures and significant energy consumption, limiting their portability and applicability in wearable devices. The newly developed sensor utilizes a hybrid VOx/VS2 heterostructure—a combination of two different semiconducting materials—enabling sensitive detection at room temperature, which corresponds to standard ambient laboratory conditions (around 20-25 degrees Celsius).

The flexibility of the sensor, achieved by fabricating it on substrates such as polymer, paper, and textiles, supports its integration with wearable electronics. Prototypes include smart bands, smart-home warning systems, and electronic textile platforms, catering to personalized, portable ammonia monitoring. The device is self-powered and portable, addressing a critical need in personal safety and environmental monitoring.

Why This Matters for Exams / Exam Relevance

This development is significant in the context of India's advancement in nanotechnology, sensor technology, and wearable electronics, aligning with the government’s focus on science and technology innovations. Important exam-related points include the understanding of heterostructures and their role in sensing, the institutions involved such as CeNS and DST, and the applications of ammonia sensors in industrial safety, agriculture, and indoor environments.

Questions can also explore concepts in flexible electronics, sensing mechanisms at room temperature, and the public health importance of detecting toxic gases. This example substantiates India's contribution to next-generation technologies worldwide.

Points to Remember

• CeNS, Bengaluru, functions as an autonomous institute under the Department of Science and Technology (DST).
• The sensor uses a hybrid heterostructure combining vanadium oxide (VOx) and vanadium sulfide (VS2) to achieve enhanced ammonia sensing performance.
• Unlike conventional ammonia sensors requiring high temperatures, this sensor operates efficiently at room temperature (20–25°C), reducing energy consumption.
• Flexibility on diverse substrates (polymer, paper, textiles) enables wearable applications, including smart bands and electronic textiles.
• The device integrates a threshold-triggered system to provide immediate alerts based on ammonia concentration zones (safe, warning, danger).
• The sensor demonstrates selectivity against interfering gases and maintains stable performance over repeated use and for more than ten weeks.
• The research was led by Prof. Angappane Subramanian with a dedicated team and is a relevant innovation in environmental and wearable sensor technology.