Vaishnavi Ranganathan
Principal Researcher
Microsoft Research, Redmond
Affiliate Asst. Professor
University of Washington, Seattle
About Me
I started my research career as a little snowflake on top of a mountain that started rolling down. Now I feel like an avalanche that just kept collecting more snow (and a decent bit of debris) along the way 😊.
I call myself a Sensing Systems Researcher, and I keep this intentionally vague owing to the wild trajectory that my research has taken me in in the past decade! Thanks to a very tolerant advisor, managers, colleagues and mentors I got to work with (and sometime lead) impactful and fun projects that I am passionate about (My research section below should give you an idea). I have so far tried to use my experience building Sensing Systems and technology to address global challenges in healthcare, agriculture and sustainability. In the era of AI, I am now on a journey to explore exciting opportunities that I can apply my learnings to. For the past year (starting end of 2024), I have been innovating with my co-conspirators at the intersection of secure AI devices, multi-modal sensing and AI personalization.
Stay tuned for more updates!
Recent Updates
- The Microsoft Undergraduate Research Internship (URI) program for 2025 has been announced. I'd highly recommend it for undergraduate students with a drive for research. I have been an URI mentor for the past three years and can confirm that it is a uniquely rewarding experience for the interns and the mentors alike. For more information refer to the URI program website
- Summer internship posting open for Networking Research Group at MSR. Apply here and email me if you work on low-power wireless communication and sensing applications and are interested in a summer internship - November 2022
- Co-chaired the first workshop on Agri Food Systems (AgSys) as a part of SenSys ‘22. The workshop was a success thanks to exciting submissions, keynote speakers (Digital Green and Strella Biotech) and, panelists - November 2022
- Appointed as Affiliate Asst. Professor at ECE, UW - July 2022
- Check out our submission “Re-Inventing the Food Supply Chain with IoT: A Data-Driven Solution to Reduce Food Loss”, at IEEE IoT Magazine. The article speaks about our research efforts in addressing challenges in the global food supply chain - March 2022
Research at Microsoft
Nov 2024 - current
Oct 2020 - Dec 2024
Feb 2019 - Sept 2022
June 2016 - current
Secure AI device interface, multi-modal sensing & personalization
Project Highlights: 2024 was a year dedicated to global policies for traceability in food supply chains. As a part of our effort to support innovation in this area, we recently open sourced several tools through project FoodVibes.
Key Features:
- FoodVibes-ai: An open-source tool that offers food and agricultural businesses an end-to-end supply chain traceability solution. The tool aims to bridge the critical information gaps in global supply chains by building on trusted ledgers to track the When, What and Where of a product through its lifetime.
- Regulatory Compliance: Adopts strategies like the "one step forward and one step backward" association prescribed by the United Nations Food and Agriculture Organization (FAO) and by the U.S. Food and Drug Administration (FDA).
- EUDR Support: Helps producers and suppliers navigate the European Union's 2024 regulation against deforestation through geospatial analytics and geo-location-based deforestation insights.
Through Project FoodVibes, we hope to address the global food supply challenges posed by the United Nations. We do this by focusing on the critical need for traceability, which can help reduce waste and optimize food production and supply. Project FoodVibes also explores using IoT and Wireless technology to enable a broader range of supply chain solutions. Fresh Sense presents a novel way of using wireless signals for pallet level produce lifetime monitoring during storage and transit of produce.
Remote Sensing:
In addition to supply chain traceability, I got to lead a fantastic team of interns and researchers on remote and satellite-based sensing. The projects were primarily around land use monitoring, deforestation monitoring, spectral, temporal and spatial extension of satellite image data, radar-reflectors for low-fidelity communication through SAR satellite imaging.
Links: FoodVibes Git Repo | TerraTrace Git Repo | FarmVibes Project | SatExt Git Repo | IEEE Publication
FoodVibes: Supply Chain Traceability & Geospatial Analytics
Project Highlights: 2024 was a year dedicated to global policies for traceability in food supply chains. As a part of our effort to support innovation in this area, we recently open sourced several tools through project FoodVibes.
Key Features:
- FoodVibes-ai: An open-source tool that offers food and agricultural businesses an end-to-end supply chain traceability solution. The tool aims to bridge the critical information gaps in global supply chains by building on trusted ledgers to track the When, What and Where of a product through its lifetime.
- Regulatory Compliance: Adopts strategies like the "one step forward and one step backward" association prescribed by the United Nations Food and Agriculture Organization (FAO) and by the U.S. Food and Drug Administration (FDA).
- EUDR Support: Helps producers and suppliers navigate the European Union's 2024 regulation against deforestation through geospatial analytics and geo-location-based deforestation insights.
Through Project FoodVibes, we hope to address the global food supply challenges posed by the United Nations. We do this by focusing on the critical need for traceability, which can help reduce waste and optimize food production and supply. Project FoodVibes also explores using IoT and Wireless technology to enable a broader range of supply chain solutions. Fresh Sense presents a novel way of using wireless signals for pallet level produce lifetime monitoring during storage and transit of produce.
Remote Sensing:
In addition to supply chain traceability, I got to lead a fantastic team of interns and researchers on remote and satellite-based sensing. The projects were primarily around land use monitoring, deforestation monitoring, spectral, temporal and spatial extension of satellite image data, radar-reflectors for low-fidelity communication through SAR satellite imaging.
Links: FoodVibes Git Repo | TerraTrace Git Repo | FarmVibes Project | SatExt Git Repo | IEEE Publication
Project Eclipse: Hyperlocal Air Quality Sensing
Pollution is something most residents of cities experience regularly, but few cities have the tools to track pollution in real-time or at the neighborhood scale. This project and the team's passion to spotlight and solve a real challenge is the reason I landed at Microsoft Research!
Project Goals:
- Bring hyperlocal air quality sensing to cities across the US
- Real-time data analytics to create awareness of local air quality conditions
- Help understand pollution's impact on local communities
- Enable real-time, neighborhood-scale environmental monitoring
As a part of the interdisciplinary team, I helped design, calibrate, deploy and maintain the network of a hundred air quality sensors in the city of Chicago to make this vision possible.
Links: Project Eclipse | Publication
Battery-Free Sensing: RF Bandaid Platform
Project Overview:
As a summer intern in the Medical Devices Group at MSR in 2016, I developed a fully-analog wearable passive sensor for continuous physiological monitoring. The vision for this work is to develop a bandaid-like device that can be worn on the body for bed-side monitoring of heart rate, breathing rate, temperature and audio. It is my pleasure to continue innovating in this area of analog, battery-free sensing and communication with my Rockstar Academic Collaborators across the world - thanks for keepign me excited folks!
Key Innovations:
- Ultra-Low Power: Device operates at 35 to 160 micro Watts power budget, harvested from 915MHz RF signals
- Plug-and-Play Design: Flexible sensor input platform that interfaces with different types of sensors
- Distinguished Recognition: Received distinguished paper award at UbiComp 2019
Research Extensions:
- Ultra-low Latency Localization: With Jingxian Wang in 2020, demonstrated sub-centimeter location tracking at sub-millisecond latency
- Beat Frequency Identification: Collaboration with Uppsala University in 2021 created a novel identification method for analog tags
Links: RF Bandaid Paper | Localization Paper | Beat Frequency Paper | More in Google Scholar
Academic Background
Graduate: PhD. in Electrical & Computer Engineering, Sensor Systems Lab, University of Washington, Seattle
Aug 2013 - July 2018
I graduated with a Ph.D. from the Sensor Systems Lab at the University of Washington, Seattle, WA. The primary focus was applying my research on low-power, wireless, sensing and communication systems towards building a Brain-Computer-Spinal Interface, a closed-loop neural implant prototype that was the first of its kind to assist in spinal-cord-injury rehabilitation.
Aug 2013 - Jul 2018
Aug 2011 - Jul 2013
Undergraduate: B.Tech in Electronics and Instrumentation Engineering/Amrita School of Engineering, India
Aug 2007 - July 2011
I received my B.Tech in Electronics and Instrumentation Engineering from Amrita School of Engineering, Coimbatore, India and was a Visiting Researcher at the Indian Institute of Technology (IIT), Bombay during my senior year in B.Tech. As an undergraduate I gained experience in robotics, MEMS and was a member of SAE India.
Wireless & Brain-Computer-Spinal Interface
Sept 2013 - Dec 2018
Research Focus: Brain-Computer-Spinal Interface (BCSI)
My PhD research focussed on a closed loop neural interface for rehabilitation and reanimation of paralyzed limbs in patients with spinal cord injury. The BCSI system development provides a system level block diagram and functional illustration along with the devices that I developed. The system is designed to stimulate in the spinal cord based on intentions decoded from neural signals recorded in the brain and close the break in communication created by a spinal cord injury.
Key Innovations:
- Wireless Power Transfer: Integrated wireless power transfer at HF (13.56MHz) for power delivery to implants
- Ultra-low Power Communication: Optimized UHF (915MHz) Backscatter communication for low-power implants
- Closed-loop Neural Recording and Stimulation: Real-time FPGA algorithms built on approximate computing for neural signal processing
- NeuralCLIP Prototype: Demonstrates stimulation triggered by on-device decoding of action intent from Local Field Potentials (LFP) recorded in the motor cortex
Technical Achievements:
To accommodate for variation in power available from a wireless power transfer link, the closed-loop system is built on novel approximate computation blocks on a FPGA. I was awarded a graduate innovation fellowship from the Washington Research Foundation to support this work on the implantable neural interface device.
Award: Washington Research Foundation Fellowship 2017: Innovation Graduate Fellowship in Neuroengineering
NeuralCLIP Prototype
The modular neural interface device NeuralCLIP which was developed as a part of this project was awarded the Madrona prize runner up in 2018.
Award: Madrona Prize 2018 - Implantable Wireless Brain-Computer Interface
Apart from this core research, I worked on other projects including energy harvesting from RF and NFC for wearable sensors, analog backscatter, wireless power transfer using phased array systems and low-overhead echolocation for localizing receivers in a HF phased array power transfer system. I also developed an FPGA implementation of the RFID EPC Gen2 protocol for performing block read and write with an Impinj R1000 RFID reader.
Publications: Dissertation Document | Brain-Computer-Spinal-Interface | NeuralCLIP Paper | More Publications: Google Scholar
Masters - Case Western Reserve University EECS
Aug 2011 - Jul 2013
Research Focus: NEMS for Extreme Environments
I received my Masters in EECS from Case Western Reserve University (CWRU), Cleveland OH. As a part of the Nanoscape Lab I pursued research on NEMS for harsh environment, high-speed switching and non-volatile memory.
Key Projects:
- Silicon Carbide NEMS: Logic and memory devices for computation at extreme conditions
- Medical Device Development: Dual purpose implantable ultrasonic assembly for detecting recurrent cancer
- DNA Sequencing: Design and analysis of nanochannel for fast DNA base sequencing
Dissertation: "Silicon Carbide NEMS Logic and Memory for Computation at Extreme: Device Design and Analysis"