Solution Overview

Solution Name

Solar Capital

One-line solution summary.

Our project aims to purify water quickly and charge electronics in a sustainable, portable, and simple fashion. 

What is your solution?

Our project aims to purify water quickly and charge electronics in a sustainable, portable, and simple fashion. We created a small-scale solar-powered device within the means of a convenient water bottle cap. UVC light can kill waterborne pathogens by forming thymine dimers in their DNA. The cap features a UVC LED that shines through the water and kills pathogens within minutes. It was tested on water from Wakulla Springs: the microbes exponentially decreased over 4 minutes of UVC exposure and over 99% of microbes were killed by minute 4. The UVC LED is powered by a solar module and rechargeable lithium-polymer battery, making it especially helpful in times of limited or no electricity. It activates at the push of a button and deactivates automatically using an Arduino circuit.

The external cable from the cap can plug into and charge electronic devices. In order to accommodate more people in more circumstances, the cap can pair with aluminum cans—turning ubiquitous trash into water sanitation containers. Supplementing the UVC LED, a conical filter was designed to clear the water of large particles and heavy metals in preparation for disinfection.

What specific problem are you trying to solve?

Over a billion people around the world lack access to safe drinking water. Tap water and electricity are compromised after natural disasters. Millions of plastic bottles litter the oceans.

Who does your solution serve? In what ways will the solution impact their lives?

Especially useful for hikers, campers, travelers, military units, natural disaster emergency kits, and individuals in rural areas or developing nations, this project is applicable to anyone in the world.

What steps have you taken to understand the needs of the population you want to serve?

We have talked with people who would potentially use our project and volunteered with organizations who work with our target audience. The CLEO Institute mentioned they were interested in including it in their natural disaster kits. There are other organizations, like 4LifeSolutions and Pure Home Water, that also work on tackling water purification for underserved communities that we can get in touch with for our project. We plan on conducting a pilot test with ten bottles and receiving feedback to further improve the design.

Which aspects of the Challenge does your solution most closely address?

Improving financial and economic opportunities for all (Economic Prosperity)

Our solution's stage of development:

Prototype: A venture or organization building and testing its product, service, or business model

Explain why you selected this stage of development for your solution—in other words, what have you accomplished to date?

For about a year, we have been working on the development of a solar-powered water purification device within the means of a simple and convenient water bottle cap. The project is currently at the proof of concept stage, with one fully functioning prototype completed. We would like the guidance of MIT experts in electrical engineering, cost-effective manufacturing, product design, and community distribution in our next steps of continuing to iterate on the design, as well as advice as we plan and execute our business and distribution strategy. We could start with a pilot test and utilize feedback to improve the product.

Where our solution team is headquartered or located:

Cambridge, MA, USA

Team Lead:

Sabrina Hu

More About Your Solution

Which of the following categories best describes your solution?

A new use of an existing technology (e.g. application to a new problem or in a new location)

Describe the core technology that powers your solution.

The core technology behind our solution is a small solar module that charges a lithium-ion battery that’s used to power a UVC LED to purify water or any other electronic device like a phone (for emergency situations).

Please select the technologies currently used in your solution:

  • Crowd Sourced Service / Social Networks
  • Imaging and Sensor Technology
  • Manufacturing Technology

What are your impact goals for the next year, and how will you achieve them?

We hope to distribute at least one hundred solar water purifiers in underserved communities that commonly suffer from waterborne pathogens.

How are you measuring your progress or planning to measure your progress toward your impact goals?

We anticipate this project will help reduce deaths and illnesses caused by waterborne pathogens. Anyone can benefit from it because everyone needs clean water.

What barriers currently exist for you to accomplish your goals in the next year?

The current prototype model is fairly costly (≈$50) because of some parts we used. We would need to create a more cost efficient circuit system instead of including a ready-made circuit board. Additionally, we need to find a way to incorporate a water filter inside to remove large particles in preparation for disinfection.

About Your Team

How many people work on your solution team?


How long have you been working on your solution?

1 year

How are you and your team well-positioned to deliver this solution?

Sabrina Hu and Shua Cho are both interested in engineering and product design. Sabrina first formulated the project idea when she was in high school and met Shua through the MIT Discover Product Design Freshman Pre-Orientation Program. Shua has experience in CAD and water quality and will work together with Sabrina to create a durable, ready-to-use product.

Your Business Model & Resources

Do you qualify for and would you like to be considered for The HP Girls Save the World Prize? If you select Yes, explain how you are qualified for the prize in the additional question that appears.


Do you qualify for and would you like to be considered for The Pozen Social Innovation Prize? If you select Yes, explain how you are qualified for the prize in the additional question that appears.


Solution Team

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