Introducing the OpenCPC™
A year ago, OpenAeros™ launched our cornerstone project: an investigation of what it would take to design and manufacture a truly open source, low-cost condensation particle counter (CPC).
We see a broadly accessible CPC as a critical tool to meet today’s growing air quality and respiratory health crises. Today, OpenAeros™ is excited to announce that we have successfully designed and begun to manufacture the OpenCPC™.
What is a CPC?
A condensation particle counter (CPC) is in many ways the tape measure of the aerosol science world. It lets us take precise measurements of the air quality conditions of a space, down to particles no bigger than 1/100th of a micrometer (often called nano-particles or PN0.1*), without having to flood the space with a test substance. CPCs take measurements of particles 25 times smaller than the indoor air quality monitors most popular today, which use only an optical counting mechanism.
The first generation of these devices dates back to the Aitken Dust Counter, developed in 1890. In the 120 years since, the CPC has become the gold standard for counting otherwise imperceptibly small particles suspended in air. In many ways the CPC is responsible for igniting today’s clean air revolution: the Aitken Dust counter helped quantify and communicate the dire impact of smog and smoke in London during the early 1900’s, changing the way the public saw both environmental and respiratory health. We believe the OpenCPC™ can do the same for today’s today public health landscape.
Waterloo Bridge is one of many of Monet’s works capturing the pollution facing London at the turn of the century.
CPCs work by harnessing the power of condensation to grow particles in much the same way that clouds form: condensing water (or other liquid) builds onto a “seed particle,” enlarging the particle until it is rendered visible. The CPC functions in a similar way, creating one cloud-like encapsulation around each tiny particle that it encounters and growing each tiny particle to a size that can be registered by a laser counter, making visible the previously undetectable. This enables measurements of particles in the nanometer size range to be known, quantified, and, ultimately, mediated in a space.
Think of it like this: imagine sitting across the room from someone tossing individual grains of sand. While you can see the motion of the throw and can experience the unpleasant grit and grime of the resulting indoor dirt pile, it would be difficult to actually see the airborne grains hurtling through the air. Now imagine that each grain of sand grows to the size of a gumball as it is thrown. You can now see the gumballs from the moment they enter the air. Describing the problem (“my coworker is throwing gumballs”) and solving it (“tell my coworker to stop throwing gumballs”) is suddenly much more manageable.
A CPC grows a nano-particle from the 10s of nanometers to the 1000s of nanometers (6-10µm for those metrology nerds out there) making low cost optical detection (like that used by the PM2.5 detectors popular today) possible.This means extreme accuracy of measurements with proven and affordable counting tools. An open source CPC creates a low-cost device that can measure what no other low-cost device can see: ultrafine particles. In turn, driving down costs and increasing access to this technology helps us better understand the exposure and health outcomes associated with the ultrafines we encounter today.
* PM0.1: Particulate Matter less than 0.1 µm(100 nanometers) in diameter
An Alpha model Open CPC TM Prototype
CPCs and Indoor Air Quality
These ultrafine particles are only about 1/500th of a human hair in diameter. Due to their small size, ultrafine particles can easily enter the bloodstream through the lungs when breathed in and then can move efficiently and harmfully to other parts of the body. These particles are a ubiquitous feature of today’s airspace. They are formed most frequently from combustion sources like cars, diesel trucks, and, as highlighted by recent controversy, gas stoves. The impacts of these hard-to-detect environmental pollutants are major: continuous exposure to ultrafine particles has been associated with a wide range of ailments including systemic inflammation, endothelial dysfunction, cardiovascular disease and hypertension, diabetes, and cancer.*
Currently available low-cost air quality testing methods just can’t detect particles this small. Historically, taking these measurements meaningfully has meant incurring an equipment cost in the hundreds of thousands of dollars for enough devices to measure air quality accurately, even in a relatively small area. We hope to bring that cost down tenfold with the OpenCPC™, enabling scientists, researchers, and community members to begin to measure and characterize (and solve for!) the presence of these ultrafines in their communities.
CPCs Can Do More Than Just Count!
While the fundamental role of a CPC is to count particles, this simple count enables a wide range of other critical tasks including:
Measurement of indoor air ventilation and filtration performance
Characterizing performance of portable air cleaners in real world situations
Assessing respirator fit
Testing filtration efficiency
Monitoring ultrafine PM0.1 for public health advisory
Why Open Source?
CPCs are proven science, and well-known to regulatory bodies and the aerosol science community. However, CPCs available on the market today cost in the range of $15,000- $30,000. As a result, the tech has been relegated almost exclusively to university and research laboratories. We believe that by leveraging the open source hardware model alongside a focus on a low-cost of materials, we can finally bridge the gap and produce the first CPC costing less than $2,000, enabling much broader adoption. With the OpenCPC, this tool becomes meaningfully available to a much wider audience including municipalities, researchers, community groups, and citizen scientists.
Our device offers a rapidly deployable solution at an order of magnitude cost reduction. Governments, businesses, and experts are much more likely to be able to access a $2,000 solution than a $20,000 one. That translates to a huge boom in the number of machines where they are needed, at a fraction of the cost.
Beyond improving access to and cost of CPCs, though, OpenAeros™ believes that an open source philosophy is critical to the impact of this endeavor. Though the first 3D printer was built in the 1980s, the 3D printing revolution as we know it was catalyzed only in the last twenty years by the creation of open source hardware. Now anyone on the globe with access to the internet and materials can make their own 3D printer and then use it to improve existing technology, to to innovate, and to create.
The ease of access and relatively low cost of today’s 3-D printer has ushered in a boom for innovation, including such world-shaping advancements as printed tissue for burn patients, on-demand customized prosthetics for amputees, and countless prototyped accessibility and mobility devices. We see a similar future as the world uses, improves, and innovates with the OpenCPC™, shaping air quality and global health for generations.
It’s inarguable that releasing the low-cost CPC design as an open-source file will not maximize profit. But we believe in the power of the scientific community and we believe that sharing the OpenCPC™ is the best and fastest way to help the most people. The open source model will enable local manufacturers and governments to create and service their own devices, creating a local ecosystem for the CPC use without complex distribution models or slow build out.
Our designs will begin to appear on our Github soon! Sign up below for notifications!
