Public Lab Wiki documentation

Detritivore Design by Mathew Lippincott

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by Mathew Lippincott

Published Q3 2014 in the Grassroots Mapping Forum #6 Order online

The average North American generates roughly 1 million pounds of waste per year.1 Some designers seek to end this waste through creating fully recyclable, zero waste products that have a ‘Cradle to Cradle’ plan for the materials.2 This production utopia ignores existing waste that cannot be easily recycled but still has significant value. Recycled materials are easy— they provide ethical satisfaction of efficiency and concern, without the difficulty of changing design practices to accept the limitations and dimensions of found objects. We should put more effort into designing around the persistent functionality of objects whose primary purpose has failed, and do so at the systems level.

In order to naturalize trash as a design material, the infrastructure of design—from software to manufacturing—needs to integrate reused components. Detritivore design sketches a path towards the systemic reuse of broken technology. Detritivores are creatures that consume decaying matter; detritivore designers design from the reuse of decaying technology, not necessarily for reuse of the products they create. We need not create a recyclable or even non-toxic product from trash so long as we squeeze the remaining value out it.

Detritivore design is an extension of parametric design, whereby the plans for an object can be re-sized and shaped prior to manufacturing.3 A parametric design is most commonly a CAD file with several rescalable features usually used for making customized stuff. Proprietary and open source CAD programs allow designers to make simple customization templates that can be fed directly into automated production systems to create shoes in custom colors or bikes with a custom fit.4 Several proponents of parametric design have gone further to create systems of interoperable components and centralized databases of components’ CAD files.5

Detritivore design is similarly software-dependent, but instead of programming in pre-production parametrics for mass customization, it uses software to enable the mass incorporation of discarded objects with a certain set of interoperable features. Software becomes a strategy for normalizing the usefulness of hardware from varied sources, rather than varying the look and feel of hardware from the same source.

Public Lab’s detritivore strategies are the same as those found in the larger DIY movement. Our methods for identification and integration of found objects, are often manual, ad hoc, and limited, built on top of systems for creating fresh new objects, not using broken old ones. In a case study of our spectrometer are seeds of a more comprehensive reuse strategy of hardware joined through software.

The Public Lab Spectrometry Kit consumes waste products and uses them to search for other, more dangerous wastes.6 Pipe cutoffs, obsolete webcams, and optical discs are sufficient to make a functioning spectrometer. The central hardware component, the diffraction grating, is made from CDs and DVDs— disposable media with extremely precise grooves. Long after the media written onto these discs decays into illegibility, they will still function as diffraction gratings, splitting light into a rainbow that can be quantified and used for material identification.

The central software component is Spectral Workbench, a web platform for spectral analysis that assists our community members in setting up and calibrating their spectrometers.7 Spectral Workbench encourages sharing data, and creates a framework for comparing and normalizing data from different spectrometers and databases of spectra. It accepts live data capture from webcams as well as uploaded photos from any camera.


We’ve made a variety of spectrometer plans, sold kits, and launched a competition to identify environmental contaminants.8 We are dedicated to this project’s continuity, but with over 200 billion CDs and over 1 billion DVD players in the world, it is unlikely that we will ever run out of hardware.9 , 10 Our design patterns ensure that optical disc spectrometry can outlast any one project or manufacturer, while our data sharing, open licensing, and practitioner community function together to distribute our system of mass-incorporation of reused technology beyond our organization.

There are commercial diffraction gratings that we could use instead of CDs or DVDs. They would even simplify the assembly of our kits a little bit, but they wouldn’t increase the accuracy of our device. Doing spectroscopy with consumer detritus is more important to our scientific program than simplifying our kits. We mail kits around the globe, but mail can’t reach all the places that DVDs and CDs already have. Detritivore design affects the permanence of trash as a badge of hope rather than dismay; we need never worry about losing access to science equipment. We’re developing a platform on top of ubiquitous trash, using its persistent nature to escape the ephemerality of both the startup culture in which we design and the relentless product release cycle of the consumer economy.


Software, and a community sharing data on the performance and function of found objects, form the infrastructure of the spectrometer’s parametricism. Such software systems need to be extended outward into design tools that encourage the reuse of trash. CAD programs should treat found objects as isomorphs— objects of different shapes that preserve a series of shared properties between them. If parametric design tools allowed for isomorphic components, especially ones linked to shared databases of found objects, then current parametric manufacturing techniques could be used to incorporate junk. In the example of our spectrometer, an object such as a “webcam” should be software-definable based on lens properties, resolution, dimensions, and image format. Software would then re-mold the mounting points around this found object. Right now we use tape, but more sophisticated strategies are needed if reuse is to go mainstream.

Being able to drag and drop isomorphic objects into a CAD program, and have software determine all the difficulties of fitting such an object into the overall design may sound exceptionally challenging, but so is long-term survival in a culture of mass consumption and disposal. As it stands, parametric design and mass customization may just intensify our use of resources, adding more custom junk to our prodigious personal junk piles. Detritivore design offers a path away from intensification of waste towards a low-intensity high tech, and a transitional culture of manufacturing between today and a Cradle to Cradle future. As we continue to build DIY examples, it is my hope that these DIY strategies inspire more detritivore design infrastructure.

Mathew Lippincott is a co-founder and director of production at Public Lab.

  1. Thackara, John. In the Bubble: Designing in a Complex World. Cambridge, Mass.: MIT Press, 2005. 12.
  2. McDonough, William, and Michael Braungart. Cradle to Cradle: Remaking the Way We Make Things. New York: North Point Press, 2002.
  3. Shih, Randy H., and Paul J. Schilling. Parametric Modeling with SolidWorks 2013.
  4. “OpenSCAD Design Tips: How to Make a Customizable Thing.” AdaFruit Blog.
  5. De Decker, Kris. “How to Make Everything Ourselves: Open Modular Hardware.” Low Tech Magazine. December 1, 2012.
  9. “Compact Disc” Wikipedia,t accessed November 2013.
  10. “DVD” Wikipedia, accessed November 2013.