Scope and Objectives

We aim at developing a smart and robust landmine detection system that has three sensing methodologies: SERS based explosive vapor-sensing nose, magnetic-field sensing, and microwave-radar imaging. Developing a system with three complementary technologies for landmine detection can enable detection with reduced false alarms and high sensitivity. Objectives include development of the three types of landmine detection technologies, characterization of the different detection methodologies, signal processing, and integration of the different sensing methodologies to form the smart integrated landmine detection system (SILDS) having a display and a transceiver system. Finally, packaging and field testing of the SILDS would be carried out.

Deliverables

1) SERS based explosive vapor-sensing nose system, for detection of explosive vapors from air/soil samples 2) Highly-sensitive Hall effect-based magnetic field sensor for landmine detection 3) Solid-state spintronic microwave sensors for Microwave radar imaging 4) Smart Integrated landmine detection system (SILDS) integrating the three sensing methodologies, a display, and communication system

Videos

Scientific Output

1. SERS measurements for explosive detection are being performed on the SERS sensor chips. 2. Fabrication of novel SERS sensor chips (for explosive vapor detection) has been carried out. 3. Finite Difference Time Domain (FDTD) and Rigorous Coupled Wave Analysis (RCWA) modeling of novel SERS substrates with large EM enhancement factors have been completed. 4. Started the UHV sputter system and have carried out initial depositions on the system. 5. Carried out the growth of magnetic tunnel junctions in collaboration. 6. Preliminary DC measurements were performed on MTJs developed in collaboration. 7. Simulations of RF sensitivity in magnetic tunnel junctions were carried out - simulations showed a sensitivity of 1500 mV/mW. 8. Developing the set-up for microwave radar imaging 9. For InAsAlSb based heterostructures to be used for magnetic Hall sensors, test wafer received from a commercial source, (Intelliepi, USA) is being tested. Optimization of layers for heterostructure for achieveing high mobility has been carried out. 10. Fabrication of magnetic field sensor devices (based on two dimensional electron gas in III-V semiconductor heterostructures such as InAs/AlSb) is currently in progress. Lithography step has been carried out and several other steps (such as etching) have been optimized. 11. The transport and noise set-up is currently being optimized for measurement of devices. 12. A bridge circuit has been completed for laboratory tests of the devices. 13. Development of machine learning based algorithms - to distinguish between different chemical signatures - has been carried out. First-level signature analysis and implementation has been started using KNN (K-Nearest Neighbors) and custom pre-processing. 14. The industry partner is developing the data transceiver and receiver system to be integrated with the devices being developed.

Results and outcome till date

1. Novel plasmonic chips based on nanowires and nanogratings were designed and fabricated for SERS sensing.
2. Provisional Patent filed on design of novel plasmonic nanostructures.
3. Fabrication of magnetic field sensor devices (based on two dimensional electron gas in III-V semiconductor heterostructures such as InAs/AlSb) is currently in progress. Optimization of the Etch Recipes was carried out. Fabricated Devices were tested.
4. Finite Difference Time Domain (FDTD) and Rigorous Coupled Wave Analysis (RCWA) modeling of novel SERS substrates with large EM enhancement factors have been completed.
5. Fabrication of novel SERS sensor chips (for explosive vapor detection) has been carried out and optimization of these sensor chips is being carried out.
6. Preliminary SERS measurements have been performed on the SERS sensor chips.
7. Carried out the growth of magnetic tunnel junctions in collaboration, while the dedicated UHV sputter system is being procured.
8. Further simulations of RF sensitivity in magnetic tunnel junctions were carried out
9. Preliminary DC measurements were performed on MTJs developed in collaboration. Provisional Patent filed on FREQUENCY AND SENSITVITY ENHANCEMENT FOR SIGNAL DETECTION
10. Developing the set-up for microwave radar imaging
11. The transport and noise set-up is currently being optimized for measurement of devices.
12. A bridge circuit has been completed for laboratory tests of the devices.
13. Development of machine learning based algorithms - to distinguish between different chemical signatures - is being carried out. First-level signature analysis and implementation has been started using KNN (K-Nearest Neighbors) and custom pre-processing. Identification of relevant public-domain Datasets has been completed. Literature Survey of relevant techniques completed.

Societal benefit and impact anticipated

Developing a landmine detection system with three complementary technologies for landmine detection will enable detection with reduced false alarms and high sensitivity. The beneficiary sector includes military forces, paramilitary forces, border police, as well as non-profits involved in finding and eliminating landmines and unexploded ordinances.

Next steps

1. Detailed Characterization of the SERS sensor chips for explosive detection 2. Growth, Fabrication of MTJ nano-pillars 3. Develop SERS sensor system for explosive vapor detection 4. Development of display and communication system,algorithms for data analysis/display 5. Characterization of Hall devices in magnetic field, implementation of gradiometry measurements, optimization of sensitivity, testing for landmine detection

Publications and reports

A. Direct observation of unusual interfacial Dzyaloshinskii-Moriya interaction in graphene/NiFe/Ta heterostructures, Avinash Kumar Chaurasiya, Akash Kumar, Rahul Gupta, Sujeet Chaudhary, Pranaba Kishor Muduli, and Anjan Barman, Phys. Rev. B 99, 035402, 2019. B. Chiral skyrmion auto-oscillations in a ferromagnet under spin transfer torque, Naveen Sisodia, Stavros Komineas, and P. K. Muduli, Phys. Rev. B 99, 184441, 2019. C. Large Spin Hall Angle in beta-W Thin Films Grown on CoFeB without Oxygen Plasma, Rajni Bansal, Gurudeo Nirala, Akash Kumar, Sujeet Chaudhary and P. K. Muduli, SPIN, 8, 1850018, 2018. D. Large spin current generation by the spin Hall effect in mixed crystalline phase Ta thin films , Akash Kumar, Rajni Bansal, Sujeet Chaudhary, and P. K. Muduli, Phys. Rev. B 98, 104403, 2018. E. Proximity effect induced enhanced spin pumping in Py/Gd at room temperature, Rajni Bansal, Niru Chowdhury, and P. K. Muduli, Appl. Phys. Lett. 112, 262403, 2018. F. P Savaliya, N Gupta and A. Dhawan, Steerable Plasmonic Nanoantennas, 31567-31586 2019. G. Nitin Gupta and Anuj Dhawan, Bridged-bowtie and Cross bridged-bowtie nanohole arrays as SERS substrates with hotspot tunability and multi-wavelength SERS response, Optics Express, 26, 17899-17915, 2018. H. A. Thomas, P. Savaliya, K. Kumar, A. Ninawe, A. Dhawan, Au nanowire-VO2 spacer-Au film based optical switches, Journal of the Optical Society of America B, 35, 1687-1697, 2018. I. Ajay Kumar Agrawal, Abhijit Das, and Anuj Dhawan, Enhanced sensitivity of SPR sensing and imaging using plasmonic nanopillar arrays, accepted for Proceedings of the conference IEEE NANO 2018, Ireland. J. Ajay Kumar Agrawal, Sarjana Yadav, and Anuj Dhawan, Enhanced sensitivity of SPR biological sensor based on nanohole arrays in gold films, accepted for Proceedings of the conference IEEE NANO 2018, Ireland. K. Anuj Dhawan, Priten B Savaliya, and Kaleem Ahmed, Plasmonic nanostructures on tips of tapered optical fibers for large EM enhancement, accepted for Proceedings of the conference IEEE NANO 2018, Ireland. L. V. Parmar, M. Suri, conference paper on Hardware learning architecture, accepted for Proceedings of the ACM GLSVLSI conference, 2018. M. N. Bhatia, M. Suri, conference paper on Analysis of chemical signatures using machine-learning techniques, submitted to the conference IJCNN-2018. N. N Gupta, RR Ghosh, A Dhawan, Nanoholes arrays as effective SERS substrates with multiple wavelength SERS response and large electromagnetic SERS enhancement factors, Plasmonics in Biology and Medicine XVI 10894, 1089418, SPIE Photonics West, San Francisco, California, United States, 2019. O. AK Agrawal, N Gupta, A Das, K Ahmed, A Dhawan, Nanostructured plasmonic gold films for enhanced sensitivity of SPR biological sensing and imaging, Plasmonics in Biology and Medicine XVI 10894, 108940M, SPIE Photonics West, San Francisco, California, United States, 2019. P. K Ahmed, AK Agrawal, S Subramanian, A Das, A Dhawan, Plasmonic nanostructured chips for chemical and biological sensing in the UV-regime, Label-free Biomedical Imaging and Sensing (LBIS) 2019 10890, 108902Q, SPIE Photonics West, San Francisco, California, United States, 2019. Q. Y Sharma, M Jaiswal, R Ghosh, A Dhawan,Hydrogen sensors based on plasmonic nanostructures present on palladium films, Proceedings Volume 11028, Optical Sensors 2019; 110282Z (2019), SPIE Optics + Optoelectronics, Prague, Czech Republic 2019. R. Y Sharma, RR Ghosh, M Jaiswal, A Dhawan, Modelling and fabrication of novel SERS sensor chips for chemical and biological sensing applications, Proceedings Volume 11028, Optical Sensors 2019; 1102830 (2019), SPIE Optics + Optoelectronics, Prague, Czech Republic 2019. S. Influence of annealing on spin pumping in sputtered deposited Co/Pt bilayer thin films, Akash Kumar, Nidhi Pandey, Dileep Kumar, Mukul Gupta, Sujeet Chaudhary, Pranaba Kishor Muduli, Physica B, 570, 254 ( 2019). T. Extrinsic spin-orbit coupling induced enhanced spin pumping in few-layer MoS2/Py , R. Bansal, A. Kumar, N. Chowdhury, N. Sisodia, A. Barvat, A. Dogra, P. Pal, and P.K. Muduli, J. Mag. Mag. Mater. 476, 337 (2019).

Patents

1. Provisional Patent filed: 201911014379 2. Provisional Patent filed: 201911042206

Scholars and Project Staff

9 Research Scholars/Ph.D. fellows have been engaged

Challenges faced

We faced hurdles in the purchase of some metals needed for the development of our chips and it was pointed out that for these metals, we need a special permission.

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