With mentions in scientific journals skyrocketing over the last few years, 3D printing is rapidly becoming a buzzword in many scientific fields. Ecology and evolution are getting in on the game too, with applications in the laboratory, field, and teaching. So as a primer to those not yet introduced to such methods, let’s cover the broad types of 3D printing and have a look at some examples where such technologies have provided novel approaches to ecological research questions, and how we may advance such techniques into the future.

Background To 3D Printing

3D printing follows the principal of additive manufacturing. In this case that means building, layer by layer, a 3D object from a material using data gathered either directly from 3D imaging techniques, or from the generation of computer aided design (CAD) models. Generally divided into three categories, 3D printers can build objects using solids, powders, or liquids.

The liquid and solid types are much more commonly used, due to their lower price bracket and convenient size. Powder-based 3D printers on the other hand are used in manufacturing where more precision is required, and are increasingly used in the health industry for custom prosthetics.

It was actually the liquid-based technique that facilitated the world’s first successful 3D printer, by inventor Charles Hull in 1983. Hull was first to patent a technique called Stereolithography (SLA), whereby a liquid resin is solidified using a precision light source. This patent resulted in the first real printed object from digital data. Fast forward to 2021, and 3D printers are widely commercially available for as little as $50.

As such, many labs have taken to purchasing a 3D printer, and now over 100 professional medical research centres and over 50% of universities have direct access to printers. So, what are the benefits?

Need Equipment? Design It Yourself!

Many lab environments will be familiar with everyday inconveniences such as looking for a missing tube rack or dealing with ordering systems for the enormous variety of materials required to run any sort of lab. 3D printing offers a wonderful solution – make your own! No more waiting for equipment, and no more stress when you break things – because you can simply print another!

In fact, 3D printing laboratory consumables has been demonstrated to reduce costs by up to 97% compared to ordering from popular suppliers. Printing your own lab equipment can also mean printing cheap spare parts for field equipment for easy repairs, or even developing custom lab equipment to suit even the most unique experimental preparations.

Of course, making custom lab kit isn’t always as easy as my excitement may make it seem, but software for Computer Aided Design (CAD) models are becoming much simpler to navigate, and so less training is required to start making custom objects. What’s better, is that our digital world is packed with every beginner’s guide you could ever need, just a Google away!

Making your own kit for the lab is great, but what about the use of 3D models in experimental design, I hear you ask.

Predator-Print Interactions

3D printers have been used to supply models for many ecological and behavioural experiments. One of the most regularly seen is plant corollas, the group of petals that surround most flowers. Used to mimic the structure of real corollas, testing how flowers attract different pollinators through creating different morphological cues, or reward-based experiments, becomes easier to investigate. It would be great to see such studies expanded to investigate the pollination ecology of nectivorous birds, or the acoustic properties of the lids of bat roosting pitcher plants.

Similarly, over in the world of predator-prey interactions, 3D printing has provided examples of trap baiting with decoys to investigate predation ecology. A recent study by Behm et al. used 3D printed models, covered in clay, to investigate the predation pressures on the brown anole (Anolis sagrei). Recent studies have even used 3D models of female Emerald Ash Borers (an invasive North American jewel beetle) as decoys to bait males to control population sizes – a cost efficient approach to an invasive pest problem.

Read more: 3D Printed Beetle Decoys

I envision an exciting future for experimental design whereby we could combine such semi-realistic models with other technologies such as camera traps for greater insights into predator-prey dynamics, particularly for species that remain elusive for in-situ observational studies.

Biophysics and Fluid Dynamics

Arguably the fields that benefits the most from 3D printing are those investigating the physical characteristics of biological structures. This is because many physical laws can be scaled with size, to permit realistic simulation of large models. Existing reviews highlight in detail how such techniques have been successfully applied to sponges, plankton, bush-crickets, and elasmobranchs.

Read More: 3D printing: Applications In Evolution and Ecology

In my own research, we have been rapidly adopting 3D printing for biophysical experiments. I bought myself a printer during the first COVID lockdown, allowing us to perform experiments at a time when travelling to collect study specimens was not so straight forward. We have been using resin-based 3D printing of large-scale models to perform acoustically scaled experiments (where the wavelengths of sounds played into the 3D printed object are decreased to mimic the wavelengths that would act around the real sized structure). This approach permits increased accessibility to experiments featuring ultrasonic sound frequencies, which usually require very expensive speakers and microphones. By printing larger models that can use lower frequency sounds to mimic true biophysical phenomena, we’re helping to pave the way for more labs to investigate ultrasounds using more affordable equipment.

Teaching

Personally, I am most excited for the ways in which 3D data and printing can be implemented into improving teaching practices in ecology and evolution. Imagine if all evolutionary morphology labs could be supplemented with interactive online software that students can use to interact with 3D geometries. Accessibility remains a key barrier to entry for many academic fields, and online teaching using such methodologies could provide alternative means of learning. Such tactile teaching could also offer a pathway for those with visual impairments to enter inaccessible scientific fields.

It also follows that museum-based teaching will also heavily benefit from digitisation and 3D printing in the future, and there are many movements aiming to push specimen collections in this direction.

Final Thoughts

3D printing offers a range of opportunities for study within ecology and evolution, increasing overall accessibility, reducing the costs of equipment, and promoting greater data transparency through the sharing of 3D files. Of course, it is also important to balance this technology with the potential mass of waste it can produce. Each application of 3D printing should consider whether alternative methods would be more sustainable. Fortunately, sustainable practices such as re-usable printing materials are becoming more common.

The uses of 3D printing are already more diverse than this article could cover, so for a deeper look into these applications, check out the following review articles, which cover some examples listed here and more!

3D Printing for Ecology and Evolution: A Hands-on Guide to Turn an Idea into Reality

Benefits and Limitations of Three-Dimensional Printing Technology for Ecological Research

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Charlie Woodrow is a PhD student at the University of Lincoln, UK. He is interested in the evolution of animal communication and ecology, and is currently researching the morphological and functional variation in katydid ears. Follow him on Twitter @CharlieZoology., or read more of his work at his Ecology for the Masses profile.

Title Image Credit: Charlie Woordow, CC BY 2.0