Copyright © Françoise Herrmann
What were you doing, when you were 10 years old? According to the USPTO inventor-profiling series, Journeys of innovation, 10-year old Gitanjali Rao was compelled to figure out what she could do to help remove lead from contaminated water in Flint, MI. A story she had heard on TV News, which led her to think that kids, just like her, were drinking contaminated water in their community, and getting sick. She thought that there must be a way to remove such dangerous substances. No wonder that in 2020, at fifteen years of age, Gitanjali was featured as Time Magazine Kid of the Year. No wonder, but how extraordinary!
Her first invention, titled System and method for detecting contaminants in water was awarded the US utility patent US11085907, on August 10, 2021. The invention, called the Tethys, after the Greek Titan Goddess of fresh water, recites the use of carbon nanotubes to detect unsafe drinking water, containing lead. Specifically, the invention comprises a carbon nanotube sensor, configured to detect one or more contaminants in the water. When the sensor is dipped in water, lead binds to the chloride ions of the sensor, creating lead chloride molecules, which increase resistance to the current, inside the nanotube. In general, the amount of lead detected is proportional to the increase in resistance to the current.
Then, the microcontroller, connected to the carbon nanotube sensor, determines the level of contamination of the water, based on the difference between the resistance encountered inside the nanotube, and a set of pre-existing resistances. Finally, depending on whether the difference is found above, or below, two different threshold levels, the water is then determined safe, moderate risk, or unsafe for drinking. The results are sent via wireless Bluetooth® connection to a mobile device, where they are gauge-displayed.
Below, an image of the Tethys system prototype inside its housing, together with the patent Figure 3D, depicting the water decontamination device 300, and insulating cartridge 303, comprising the carbon nanotube sensor. Both the image of the prototype, and the patent Figure 3D, depict the system inside a housing, designed to protect all the components of the Tethys system.
The image of a Marvel comic book cover, depicting Genius Gitanjali, the young Tethys inventor, is also included below, together with the abstract of her first invention.
Devices, systems, and methods for detecting contaminants in water are provided. A device may include: a sensor configured to detect one or more contaminants in a liquid when the sensor is dipped into the liquid; a computing device connected to the sensor, the computing device being configured to determine a resistance of the device when the sensor is dipped into the liquid; and a wireless electronic device connected to the computing device via one or more wireless links and configured to receive the resistance of the device when the sensor is dipped into the liquid from the computing device, and the wireless electronic device determines a level of contamination in the liquid based on a difference between the resistance of the device when the sensor is dipped into the liquid and a set or predetermined resistance. [Abstract US11085907]
References
Gitanjali Rao - Time Kid of the Year 2020.
https://time.com/5916772/kid-of-the-year-2020/
Prisco, J. (Feb. 15, 2018). Gitanjali Rao wants to make polluted water safer with lead-detection system.
https://www.cnn.com/2017/11/28/health/gitanjali-rao-young-scientist-winner/index.html
USPTO – Journeys of innovation: One girl’s commitment.
https://www.uspto.gov/learning-and-resources/journeys-innovation/field-stories/one-girls-commitment
