St. Anne's-Belfield School InvenTeam

Charlottesville, VA
Lightweight, Compact Water Filter

The St. Anne’s-Belfield School InvenTeam invented CHINChILLA (Compact Hybrid In-situ Nano-filtering Chemical-removing Ion-exchanging Lightweight Lixiviating Appliance). The filtration design is a stack of
multiple filters that can remove pollutants and deliver potable water with minimal losses. CHINChILLA is easy to use and disposable. Whether the use is in the home following an industrial spill or for disaster relief,
CHINChILLA can filter at least a liter of water every day for a week. The target cost of the filter is less than $5 to facilitate production in large numbers for rapid deployment to the area in need.

Watch their 2015 EurekaFest Video


May 22, 2015

Pictured left, Lauren runs tests on a sodium polyacrylate cell. Brackish water is poured through a humidifier tube and meets the sodium polyacrylate in the plastic cell below, which absorbs the water, leaving the salt behind. The water then drips through the cell and into the beaker below, while the salt remains in the cell.


May 22, 2015

The Upper Filter recently ran a full test on our newest working prototype, with promising results. The sample water included decomposed plant matter, motor oil, lawn fertilizer, cat feces, and salt. After passing through our Upper Filter, we were pleased to find that the contaminants appear to have been removed (pictured left)


April 21, 2015

We attended Genius Hour at the annual TomTom Founders Festival in the Belmont neighborhood of Charlottesville. Many people stopped by to ask about our project and our progress. The weather started out beautifully but turned to rain by the end of the afternoon. The team had fun discussing our work and was buoyed by community support.

April 21, 2015

We're pleased to have received congratulations from some of our elected officials, Governor McAuliffe, Lt. Governor Northam, and Senator Kaine.  










February 4, 2015

In the ongoing attempts to remove salt from a saline solution, the Lower Filter team spent the morning constructing an ion exchange column made from a plastic cylinder filled with cation exchange resin and a saline solution of 5000 ppm. We spent the majority of the time creating the saline solution and attaching the cylinder to a stand. Porter handled the cation exchange resin while Molly and Lauren worked to create the proper solution. Some water immediately began to pass through the cyclinder; it is not yet clear whether the saline content was removed in the process.

January 26, 2015

Jisoo and McKenna tested the first full prototype of the upper filter. This version uses a passive feed that separates floating materials, e.g. oils and floating solids, by having the water overflow the feed vessel until the floating materials have overwashed--works kind of like a kitchen fat separator. The remaining water is then released into the second stage, currently housed in 2" pvc pipe.

January 26, 2015

The upper-filter team examined the remains of filtration media following a test of the second stage of their filter. Scott had brewed up a pretty nasty sample that was full of biological contaminants by the time we used it. The media seems to have survived the encounter, but we still need to filter out smaller suspended materials.

January 23, 2015

Friday morning, the Lower Filter team applied sealants to our RO Film Flow Generator prototype. First, we applied liquid gasket to the inside of the bottle cap. Then, threadlocker fluid was applied to each of the two luer locks that attach the syringes to the bottle. The sealant takes about 24 hours to dry; next week we will attempt to pass water through the RO film. 

January 8, 2015

Our upper-filter team, lead by Jisoo, is pursuing several options for removing suspended solids. One method uses gravitational pressure with a prefilter that allows the floating material to wash off the top of the filter. The second method uses a large extraction syringe and two check (one-way) valves to draw water from below any floating debris and oil and actively force it through initial filtration.

January 8, 2015

Andy and Jacob tested syringe microfilters to determine the pressure needed to drive water through the filter. Fortunately, it seems like a modest depth of water (pressure head) will suffice.

November 14, 2014

We made some progress developing seals for the reverse-osmosis films. Using a water-sample bottle and some plumbing putty, we were able to seal the film to prevent leakage from the fittings. The rate of permeate through the film seemed good (see video), however, we did not achieve the desalination we expected, so we're doing additional research. We're concerned that we might have damaged the film while sealing it or perhaps it requires some treatment before use.


October 17, 2014

Things were exciting at St. Anne's-Belfield School following the press release of this year's Lemelson-MIT InvenTeams. We're honored to have the opportunity to develop the emergency water filter that we call the CHINChILLA (Compact, Hybrid, In situ, Nano-filtering, Chemical-removing, Ion-exchanging, Lightweight, Lixivating, Appliance).