Build Yourself Some Science: Inside Public Lab’s Open Source Tools

Maker News Science
Build Yourself Some Science: Inside Public Lab’s Open Source Tools

In the summer of 2012, I came across an event listing for a kite building workshop and the next thing I knew I was on a loading dock in Brooklyn, NY, building kites and solar balloons with two of Public Lab’s founders. Seven years later, I am Public Lab’s Open Hardware Community Manager — one of the people who reaches out to people who might be interested in building, learning or exploring with DIY environmental tools.

Assembling kits at the Texas Barnraising event

Public Lab members are people who are passionate about finding ways to build and use tools to solve real-world research problems, and who use those problem solving skills to connect with and improve aspects of their communities. We’re excited about the contributions that everyone brings to the table: part makerspace, part research community, part organizing platform, Public Lab brings people who are interested in making change together.

Collaborating on satellite receiving hardware at the Cocodrie, LA Barnraising event

Getting involved with Open Hardware projects is as easy as showing up (in person at an event, or joining an online site or forum), introducing yourself and expressing an interest. Public Lab celebrates a diversity of projects, skills, and types of contributions — in addition to tech oriented projects, our Open Hardware contributors include gardeners, emergency responders, illustrators, kite and balloon enthusiasts (obviously!), biologists, community organizers: people with skills of every type and level who are excited to learn and share with others. We run regional events called Barnraisings designed to bring local groups, environmental organizers, and DIY folks together. We present our work at Maker Faires, and hold workshops around the world so that other people can connect with the things that a big, open community has to offer.

Monitoring stormwater with youth from Groundwork New Orleans

We welcome anyone with an interest in using or making tools in their local environment to reach out to us — we’re excited about living in a world where applying our skills (maker skills or otherwise) to environmental issues can lead to a healthier world for all of us.

Here are a few of the kits from our community.

Coqui conductivity meter



The Coqui (named for a Puerto Rican frog with an especially loud and recognizable call) determines conductivity in water. This tool doesn’t require a lot of equipment or electronics experience to build: the circuit measures conductivity between two wires, and communicates that information through a speaker as a that tone increases in pitch as conductivity increases. In something like distilled water, this will be relatively low, but with the introduction of materials with greater conductivity (salt is one example), it will increase.

High or low conductivity isn’t necessarily bad — sea water will naturally have a higher conductivity than fresh water, for instance, but using a tool like the Coqui to test multiple spots along a waterfront to scan for trends or changes in the conductivity can help you to identify spots where something might be entering or moving through the environment—either from the built environment (say, runoff from an industrial site, or an underwater drainage pipe), or naturally, as fresh water enters the system.

This tool was created as part of the Open Water Project at Public Lab, designed in part for use in education. You can use this along with a short handbook developed by Catherine D’Ignazio called Sensor Journalism: A Guide for Educators, which outlines ways that data collection can be used to tell compelling stories about issues in
the environment.



The Community Microscope is one of several approaches to microscopy in the open source community. Our inspiration for this kit came from projects that preceded us, including the OpenFlexure Microscope, Hackateria’s DIY microscopes, OpenPatch of Indonesia, and countless examples of handmade magnification tools that people have built and used for centuries. This version was developed in collaboration with Parts & Crafts (a makerspace and community workshop in Sommerville, MA).


Public Lab’s microscope can be assembled using a variety of materials and techniques — two platforms hold a camera and a slide, and a simple mechanism made from rubber bands and wingnuts allows a user to focus the device. The simplest version of the microscope uses a USB webcam with a flipped lens, but other versions can be made with higher quality lenses or traditional microscope objectives. Raspberry Pi cameras can let you connect over Wi-Fi, and changing the orientation of the stages and lights let you experiment with different ways to view a sample.

This kit is especially great for examining microorganisms in water samples. The basic webcam it has a field of view of about a millimeter — small enough to clearly see things like plankton, amoebas, and tardigrades! It can also be paired with a sample collection tool like BabyLegs (page 24) as you investigate different kinds of pollution in your water.



This tool helps analyze the chemical composition of a sample. By passing light through a sample and scattering it so that it is captured by a camera as bands of color, and then transforming those bands into a graph that gives more precise data about highs and lows, it is possible to start identifying chemicals that may be present in the sample.

Public Lab users generally share their results on Spectral Workbench (, an online tool that will convert your images (they’ll look like rainbows) into graphs. The highs and lows on various points of the graph can help you to identify chemical components in a sample, and by comparing the spectra of an unknown sample to the spectra of something that has already been identified it is possible to draw conclusions about what may (or may not) be present.


The spectrometer and Spectral Workbench are some of Public Lab’s earliest tools; by breaking an otherwise expensive tool into more accessible/DIY parts (Lego or cardboard, webcams or Raspberry Pi cameras, recycled DVDs) it means that spectroscopy is a research method that anyone can explore.



The Simple Air Sensor is a prototyping and onboarding kit to help you get started learning the basics of particulate matter air pollution, electronics, and the design of experiments, without having to learn how to program. It’s inspired by open source work from Julieta Arancio, Gustavo Olivares, and many others.

On the unit, a realtime readout changes color when the sensor reads differences in air quality. You can study the performance of the sensor itself by watching changes in the colored light readout in the presence of different sizes of particle (dust) in different humidity conditions.

This sensor circuit uses the same type of particle detector as the PurpleAir sensor, but differs (and is cheaper) as it only uses one as compared to PurpleAir’s two. It also does not include a temperature/humidity/pressure sensor as the PurpleAir does, and instead of logging into either the cloud or to the device itself for readings, ours displays its changes via the colored light.



This simple DIY trawl can be used to collect water samples for analysis. A trawl works by letting water pass through a net while materials are caught inside. Usually a trawl is towed behind a boat or set up along a shoreline, river, or someplace where running water can pass through it. What remains in the net (in this case, made from a pair of pink tights!) can be transferred to a sample bottle and examined under a microscope.

BabyLegs was developed by Max Liboiron and the Civic Laboratory for Environmental Action Research (CLEAR) to collect samples for marine microplastics research (see page 27). Microplastics enter our waste stream as larger plastic breaks down and become an issue as they are consumed by marine animals and absorbed into the environment, putting people, animals and marine ecosystems at risk. Samples gathered from the ocean surface can be examined under a microscope. Even though microplastics are quite small, in many cases it is possible to identify the type of plastic and hypothesize its source — this not only helps us to recognize what issues we may be coping with locally, but also track how waste travels through marine environments.


Trawls like BabyLegs can also be used to investigate the microbiology of an ocean, pond, lake or creek (really, any body of water). Microorganisms are also captured in trawl nets — organic matter (sediment, plant matter) can be home to all kinds of tiny organisms that you can see under a microscope.



The Infragram Pi camera was designed to help visualize plant health. As plants convert light energy into chemical energy via photosynthesis, most plants absorb light from the blue and red range of the spectrum and reflect away the infrared range. By using cameras that can capture infrared, it is possible to get a sense of how well a plant (or group of plants) is converting light into food. By comparing pictures of similar plants growing in different conditions, it is also possible to hypothesize about the environmental conditions that might be affecting plants. One example might be in a controlled experiment, where two identical plants are being grown in different kinds of soil or fertilizer. In environmental work, people use infrared (IR) photography to survey larger areas in the hopes of seeing how and where soil and vegetation may be impacted by pollution. An easy way to survey a large space (like a field, or waterfront) is to capture photographs from above — lots of Public Lab contributors use kites or balloons to do aerial mapping.


The Infragram Pi camera is small and lightweight, which makes it a good choice for aerial photography. It uses either an infrared Raspberry Pi camera (these can be purchased), or an existing camera with its infrared filter removed. Infragram software (available through Public Lab’s store and website) lets a user connect to a live camera feed over a Wi-Fi network and download to a memory card. Once images are downloaded, the colors can be processed on or Image Sequencer (an image processing tool developed with the support of the NASA AREN project).







Discuss this article with the rest of the community on our Discord server!
Bronwen Densmore

is Public Lab’s Open Hardware Community Manager. She comes from background in art, fabrication and academic librarianship. She lives in Brooklyn, New York.

View more articles by Bronwen Densmore


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