Research Areas

Renewable Energy | Terahertz Technology | Artificial Intelligence based Healthcare systems

Renewable Energy

Smart Power Windows:

SPW generates electricity from NIR wavelength without hindering the visible light. These windows, when used in building integrated photovoltaics, generate electricity, reduce the energy consumption in air conditioning systems and artificial lighting as it blocks heat-causing radiation and provides natural lighting. These windows have the potential to fulfill net-zero energy buildings.

                                                      

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Solar PVT co-generation System:

Solar PVT Co-Generation is a dual output system which can give both hot water and electricity simultaneously. A typic polycrystalline solar panel has an efficiency of 15% only while rest goes as waste heat. This waste heat from the panel is tapped by the efficient design of the heat exchanger which not only extracts the heat but also cools the panel thereby boosting its electrical output significantly. The idea behind the hybrid PVT system to save space (>50%) with the effective utilization of waste heat.

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IoT Enabled Solar Tree:

The IoT enabled smart solar tree is a decentralized power generation unit which can be scaled and configured according to location and application. Ability to provide tuned solar power generation curve depending on application makes it unique. Also, optimally designed solar tree helps in reducing shading losses and provides maximum energy generation per unit ground footprint area. Integration of distributed sensing, surveillance and customizable sensors makes the solar tree deployable in smart cities, agricultural lands, border security area, EV charging stations and so on. The research activity is in line with the smart city mission of the government of India.

                                                      

  • Full-scale working model of two 500 W solar tree installed at CSIR-CEERI, Pilani.
  • Sumon Dey, Madan Kumar Lakshmanan, Bala Pesala,” Optimal Solar Tree Design for Increased Flexibility in Seasonal Energy Extraction,” Renewable Energy, 125, pp 1038-1048 (2018). IF: 4.36 https://doi.org/10.1016/j.renene.2018.02.017
  • IoT enabled solar tree technology has been transferred to M/s. Star Rising Energy Pvt. Ltd, Jaipur

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Thermophotovoltaics:

Thermophotovoltaics is a promising approach to convert heat energy into electricity with applications in portable power generators. Studies based on intermediate filters and photonic crystals have shown significant improvement in system efficiencies for combustion and solar-based TPV systems. Here, the key goal is to engineer directionally and spectrally selective thermal emitters ideally matched to the bandgap of a solar cell using high contrast gratings. Spectrally tuned optimized emitter structure will show maximum transmission of convertible photons (above the bandgap) while suppressing unconvertible photons (below bandgap) reflecting to the combustor thus reducing the heat losses in the photovoltaic conversion, increasing the combustion system temperature thereby contributing to an overall increase in TPV system efficiency.

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Solar Powered Hydrogen generation:

Solar powered hydrogen generation is the cleanest and renewable way to produce hydrogen with less carbon footprint. By combining the functions of light harvesting and electrolysis together, abundant solar energy can be directly converted to hydrogen fuel. In general solar-driven hydrogen production is performed by three types of devices: Photocatalytic cells, Photovoltaic (PV) H2O electrolyzers and Photoelectrochemical (PEC) cells. We focus on PEC water splitting with the aim to develop suitable photoelectrodes and also to build a sustainable unbiased PEC water splitter.

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Green Solar Cells:

The conventional first generation silicon based solar cells, though highly efficient are highly energy intensive and therefore expensive in terms of manufacturing.  To tackle this, extensive research on Dye Sensitized Solar Cells (DSSCs) are being performed to develop them into a commercially viable alternative to silicon solar cells. The most widely used dyes in DSSCs are toxic rare metal based complexes which are expensive. This has led to the search for potential alternative sensitizers. Natural dyes extracted from plants are being explored as an alternative due to their easy availability, nontoxicity and biodegradability, however, the main bottlenecks in using natural dyes is their low efficiency and lifetime. The present work is towards exploring various pathways for development of enhanced efficiency green solar cells which can be used for integration in disposable, portable applications.

                                       

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Terahertz Technology

Terahertz spectroscopy:

Engineering novel organic molecules with prominent signatures in the terahertz range

 Novel organic molecules have been designed with unique and tunable resonances in the THz region by incorporating electronegative atoms and varying the molecular masses and hydrogen bond strengths. Molecules with THz resonances, especially less than 2 THz are very hard to counterfeit since these resonances originate from bulk vibrational modes and hence can be used as THz tags for anti-counterfeiting applications in currency notes, pharmaceutical drugs and security documents.

                     

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Terahertz spectroscopy to understand cement hydration dynamics for engineering rapidly setting concrete structures

Terahertz (THz) spectroscopy and Density Functional Theory (DFT) simulations have been employed the study the variation in hydration dynamics of cement and its chief constituents due to incorporation of nanosilica. By tracking the variation in intensities and polymerization effects resulting in shift of key resonances, studies show that THz spectroscopy has been able to detect the early stage reactions of the cement constituents due to nanosilica incorporation.

                     

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Understanding the interaction of water in fuel cell membranes

THz spectroscopy is being employed to understand the interaction of water with fuel cell membranes such as Nafion and SPEEK. This is important as the fuel cell performance is highly dependent on the membrane hydration.

                     

 

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Terahertz NDT:

A CW THz imaging system has been developed which can successfully detect and differentiate between various hidden objects in packages, internal defects in concrete and GFR-Balsawood composites and measure optical thickness pharmaceutical tablets. Based on the application, the imaging system can carry out the NDT measurements in transmission and reflection mode.

                                                      

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Artificial Intelligence based Healthcare systems

Our research focus is towards the development of wearable devices integrated with machine learning algorithms for an obtrusive and continuous health monitoring applications.

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