How do we ensure the world has enough clean drinking water? Ask the Namib desert beetle! 

By Parisa Moazzam

Approximately 2 billion people of the world’s population are living with the risk of reduced access to freshwater resources. As a result, three in ten people lack access to safely managed drinking water services and water scarcity affects more than 40% of the global population. Each day, unfortunately, nearly 1,000 children die due to unsafe water supplies. So, water scarcity is one of the largest issues facing us today.

Finding a clean water source and installing systems to transport this water to people is time consuming and very, very expensive. So, is there a simpler, cheaper way to solve this worldwide problem? The answer may come from a very unusual source – the Namib Desert Beetle.

I am Parisa Moazzam, a PhD candidate at UNSW, and my previous research has focused on looking to nature to solve human problems. In particular, as a scientist, I was interested to see whether nature could provide me with some clues to help modify synthetic materials (such as aluminium surfaces in medical devices) to make them more biocompatible (i.e. more resistant to bacterial attachment in order to reduce risk of infection for patients). Whilst pursuing this research, I realised we needed to look to nature for ways to alter the superhydrophobicity/superhydrophilicity of the surface. This is when my supervisor and I found a very interesting structure on the Namib desert beetle.

The Namib desert beetle lives in one of the driest areas in the world. How does it survive here? It turns out that the surface of the beetle’s back has a unique structure that allows it to collect tiny droplets of water from mist and fog. This process is effective and efficient, allowing the beetle to collect enough drinking water to survive in one of the harshest climates on Earth with little, to no energy expenditure. My colleagues and I wondered – is it possible for us to recreate the structure of the desert beetle’s back within the lab to mimic its unique properties?

We noticed that the underlying surface of the desert beetle’s shell was mostly hydrophobic (water repelling). However, it was covered in a series of bumps that were porous and hydrophilic (water attractive).

To mimic this, we used a fascinating biopolymer called polydopamine (PDA), and applied a technique called negative photolithography to produce a porous membrane surface. We then coated SU-8 surface with PDA to creating hydrophilic, porous bumps, just like the desert beetle’s back. We placed these PDA coated bumps on a hydrophobic material called polypropylene (PP) and measured how much water was collected by the new surface. We found the surface collected a very high rate of water from mist. Excitingly, we found not only was this structure economically viable to be fabricated on a large scale, but due to the porous nature of the polypropylene membrane, the water collection rate could also be substantially increased by using vacuum pressure which is shown in the below figure.

We managed to publish our findings in the Desalination journal. We even include details in our paper about how to fabricate the material into a water harvesting device that could be used for people to make clean drinking water. Importantly, by using a simple, cost-effective, green and rapid method of negative photolithography, we have found a means towards achieving fresh water in a humid environment without consuming energy. Thus, this material could be a possible solution to the world’s water crisis and help change the lives of millions of people.

So now that we have successfully created a synthetic surface that could harvest water from thin air, what’s next?

There are many other potential applications for these surfaces including open-air micro-channel devices, lab-on-chip devices, and controlled drug release coatings. Bio-mimicking the desert beetle’s hierarchical surfaces could be a pathway towards future work involving testing other techniques such as 3D-printing to scale up the work.

You can check out our work here: Link

Follow Parisa on Twitter (@parisa_mzm)

Outreach at the Sydney Girls High School Science Conference

By Dr Yulian Cao

On Thursday the 27th of June, five of our UNSW Women in Maths and Science Champions, Nicole Green, Raisa Rafique, Yulian Cao, Emily Vohralik and Sarah Topfer had the amazing opportunity to be judges for the Sydney Girls High School Science conference. The conference is an annual competition where Year 9 students present the outcomes of a research project they have conducted to an expert panel. It is a unique opportunity for students to interact with STEM professionals and for STEM professionals to be inspired by the young minds of the future.

UNSW Women in Maths and Science Champions with the two winners of the Sydney Girls Science Conference.


Sydney Girls High School Science Conference.

The champions helped judge 25 research projects on the night, pre-selected from a pool of over 150 written project reports. Judging occurred in two stages – a preliminary stage where students were split into six groups and presented their project to a judge followed by a final stage where the best student from each group presented their project for a second time in one of two finals and two winners were determined.

Like any scientific investigation, the judging criteria for the students’ project included major considerations such as experimental design and data analysis. It also focused on the ability of the student to communicate their ideas and demonstrate understanding of topic and presentation.  The latter was a particular highlight for the UNSW Women Champions who were able to provide students with valuable feedback based on their science communication training as part of the UNSW Champions program.

Judge notes for the Sydney Girls High School Science Conference.

Early career researcher and UNSW Science Champion Yulian Cao was particularly impressed by some of the unique scientific questions posed by the students including “Is there a relationship between the concentration of plastic in water and how the water absorbs or loses heat?” and “The effect of different types of moisturisers on skin hydration.

“The student’s experiment design and data analysis strongly support their proposed topics; their presentation and communication skills were good and they even answered all judges’ questions promptly.” said Yulian. “This is an amazing accomplishment considering many experienced scientists find it challenging to perform well in all these areas.”

Another UNSW Women Champion also commented, “This has been a chance for me to learn from the high school students. They did very good work!”

Well done to all the students who presented on the night and the UNSW Champions look forward to next year’s conference.

One of the winning students presenting her project on “the effect of different types of moisturisers on skin hydration.”


Follow on Twitter:

Yulian Cao:  @YulianCao

Nicole Green:  @NicoleFGreen

Raisa Rafique: @RaisaBangladesh

Sarah Topfer: @SarahTopfer_

Emily Vohralik: @EVohralik