3D technology can save a money..

Replica toys made using a 3D printer. Photograph: Isifa/Getty Images

Working replicas of expensive scientific equipment could be made for a fraction of conventional costs using cheap 3D printers, possibly saving developing world labs thousands of pounds each time, says a researcher whose has written a book on the subject.

This and similar advances mean the age of appropriate technology – affordable, sustainable solutions designed and built to meet local needs – may be here, argues Joshua Pearce, a materials science and engineering professor at Michigan Technological University in the US, in an article in last month's Physics World magazine.

"For example, my lab developed an open-source 3D printable colourimeter for water testing, which costs $50 (£30) instead of $2,000," says Pearce, whose book is called Open-Source Lab: How to Build Your Own Hardware and Reduce Research Costs. The cheaper version worked as well as the $2,000 one, he adds.

"Let us say it cost us $3,000 to develop [the instructions for a cheaper device] the first time, primarily for the labour costs, and Brazil does something similar for another water-testing tool that they currently buy 10,000 units a year from Germany," he says. "They pay $3,050 for the first one – that's an investment – but only $50 for each additional one, saving themselves over $19m in the first year."

Pearce says with the advent of 3D printers, companies relying on extracting monopoly prices on products for which there is already an equivalent open-source alternative must either reduce their margins or continue to innovate to remain economically viable.

"If you print out – instead of buying – a single magnetic tube rack and buy the magnets yourself, you can easily justify the cost of a RepRap [self-replicating] 3D printer to do it," says Pearce. RepRaps cost about $1,000 assembled, and can be put together from parts costing under $500.

The idea of appropriate technology to deal with poverty was used as early as the 1970s by the World Health Organisation (WHO), when villagers were encouraged to make water pumps and farming tools. But3D printing has given the concept a boost, Pearce says.

The WHO's efforts worked well, he says, but took in only one village at a time. "There was incredibly wasteful duplication of effort to solve nearly identical problems all throughout the world."

Now, with affordable 3D printers on sale, widespread internet access and the open-source movement gaining followers, more people can use, study, copy and change a design for free – and share the improvements online, Pearce says.

He cites a range of initiatives that are making appropriate technology a more-realistic prospect. The Wikipedia-like website Appropedia lets users develop collaborative solutions in sustainability and international development.

There are other initiatives that develop or make use of free online instructions to build research equipment, for example the Tekla Labs online community or an inexpensive microscope created as part of the OpenLabTools initiative. Sites such as Thingiverse host 3D printable designs for everyone to use. And open-source programmes such as OpenScad allow users to modify existing designs of 3D-printable lab equipment to meet their needs.

Talented scientists in many developing countries lack the research instruments they need, says Carlo Iorio, deputy chairman of the European Physical Society's Physics for Development group. Many poorer nations may be "full of good theoreticians, but because of the lack of instruments, applied sciences that are the core of the wealth in the [developed world] are greatly neglected there", he adds.

The Physics for Development movement is trying to change that by getting people to develop high-quality technology from local or recycled materials. Pearce says the movement may encourage developing nations to introduce policies to support the funding of open-source scientific equipment and further bring down its cost.

Practical Answers, a knowledge-sharing service run by the charity Practical Action, has a large open-source database of appropriate technologies. Rob Cartridge, who oversees the service, says the open-source concept is crucial for delivering technology justice, as it gives people a right to decide, choose and use technologies that assist them in leading the kind of life they value in a sustainable way.

"Whether you are talking about a water pump in Zimbabwe or a gyroscope designed to monitor earthquakes and landslides in Peru, it is critical that technologies are not hidden behind intellectual property rights or subscriptions that make them inaccessible to the poorest communities," he says.