Name of the speaker: Dr. Suman Kundu
Title: Inkjet-Activated CMOS Pixelated Capacitive Sensor Platform for Multispectral UV Imaging and Ultrahigh-Resolution Humidity Sensing
Date and Time: 15th October 2025, 3:00PM
Venue: S. V. Narsaiah Auditorium, IAP Department.
Future autonomous always-on Edge-IoT nodes must be able to sense and interpret diverse environmental signals while operating under strict energy budget. Traditional systems using discrete sensors with microcontroller-based readouts are not sustainable, as they increase complexity, power use, and cost. Thus, a more scalable and integrated solution is needed to detect multiple parameters such as humidity, gases, odors, and light. In this context, CMOS (Complementary Metal-Oxide Semiconductor) technology offers an energy-efficient, chip-scale platform but faces challenges with low material compatibility and increased fabrication complexity. To address this, we use a CMOS Pixelated Capacitive Sensor (PCS) arrays containing 3072 microsensor pixels in ~ 1 mm2 area, each capable of detecting extremely small capacitance changes (10-18 -10-15 F). Activation of the PCS array is achieved via inkjet printing of picoliter-scale droplets (~ 10 pL) of various functional materials. By precisely printing metal-oxide nanoparticles, we create filterless CMOS multispectral UV imagers based on the ‘photodielectric effect’, while hygroscopic carbon black ink enables rapid-response humidity sensors. The dense pixel array provides ultrahigh spatial resolution (~ 10 µm), allowing distinct visualization of micro-dimension stomatal features on the plant leaves. Furthermore, by modifying low-cost (50-500 €) consumer-grade inkjet printers for precise multi-material printing, we integrate humidity and UV sensing into a single CMOS platform. These developments open new pathways toward versatile multisensing arrays for applications spanning environmental and health monitoring, as well as secure data transmission.
About of Speaker: Dr. Suman Kundu is currently the Group Leader in Embedded Systems at the Department of Microsystems Engineering (IMTEK), University of Freiburg, Germany.
He previously worked as a Postdoctoral Researcher at the Microelectronics Department, Delft University of Technology, Netherlands (2022–2024), and at the School of Electronic Engineering, Dublin City University, Ireland (2021–2022). He obtained his Ph.D. from the Centre for Nano and Soft Matter Sciences (CeNS), Bangalore, under the supervision of Prof. G. U. Kulkarni, in April 2021.
His research interests include embedded sensors, CMOS-based sensor arrays, energy-autonomous sensing systems, printed-flexible electronics, gas and humidity sensors, photodetectors, neuromorphic devices, and the development of smart prototypes for home, industrial, and environmental applications.