Water Purification Through a Straw

To help alleviate health issues caused by pathogens in water, a team of CU Boulder mechanical engineering students collaborated on a senior capstone project last spring to create PureSip, a prototype for a water purification system.

Housed inside a bottle lid, PureSip uses ultraviolet LED technology to purify water through a straw as the user drinks — killing 99.9% of germs and eliminating the need for single-use plastic bottles.

To support product adaptability, the bottle lid can be used with common reusable water bottle brands such as Nalgene and Hydro Flask. 

The purification process begins when the spout of the bottle lid is flipped open and can continue purifying for a total of 40 minutes before the batteries need to be recharged. With the assumption a user drinks at a certain pace, the team calculated that amount of time to equal 30 liters of water. On average, this would equate to 60 disposable plastic water bottles. 

The PureSip team members — Jack Figueirinhas (MechEngr’23), Jack Isenhart (MechEngr’23), Mackenzie Lamoureux (MechEngr’23), Ella McQuaid (MechEngr’23), Marie Resman (MechEngr’23) and Carlos Yosten (MechEngr’23) — made a point of using lithium-ion polymer batteries because they’re rechargeable, have a long battery life and are more compact than other battery options. 

The PureSip team pitched their idea at the 2023 New Venture Challenge, a cross-campus program and competition that gives aspiring entrepreneurs a chance to win money to fund a startup. The product received third place in the climate-focused section.

Lamoureux, PureSip’s product manager, said last spring, “We hope that our product can help reduce plastic pollution, and more particularly help eliminate the need for single-use plastic bottles.”