Category: Transdisciplinary research

Insect wings – tackling antimicrobial resistance

Last April, Arabella Heath, a Biochemistry undergraduate student, and Mia Hughes, a Chemistry undergraduate, joined IMSE for a day to experience the work environment in an Operations team. Together, they explored the topic of antimicrobial resistance and how we can keep antibiotics working by combining molecular science and engineering research. Coincidentally, a couple of weeks ago, the U.K. government updated its strategy to tackle antimicrobial resistance for the next 5 years. In this blog, Arabella and Mia explore how the surface of insect wings is inspiring innovation on antimicrobial ‘smart’ surfaces to reduce bacterial infections in hospitals.

The prevalence of antimicrobial resistance

Summer is approaching, and we are all dreading the familiar sound of insects buzzing that accompanies the season. But who knew that studying some insects like cicadas and dragonflies might hold the key to tackling antimicrobial resistance (AMR)? AMR occurs when antimicrobial treatment is no longer effective at treating bacteria, viruses, fungi and other parasites. It leads to increased infections rates and severe illnesses. AMR is a major threat for the development of global public health. AMR caused an estimated 1.27 million deaths in 2019 worldwide and this is set to rise to 10 million by 2050. This issue requires new and innovative solutions because evolving bacteria are outsmarting our current available antibiotics.

Steps on how antibiotic resistance happens. 1. Lots of germs, some are drug resistant. 2. Antibiotics kill the bacteria causing the illness, as well as good bacteria protecting the body from infection. 3. The drug-resistant bacteria are now allowed to grow and take over. 4. Some bacteria give their drug-resistance to other bacteria, causing more problems.
How Antibiotic Resistance happens. Image credit: Lumen learning.

Insects wings v Bacterial infections

Remember as a child, trying to stretch bubbles into different shapes before they pop? Now, imagine pulling apart millions of little bubbles before they can float away. This is exactly how cicada’s wings work. They are lined with rows of spiky nano-protrusions which pull on bacterial ‘bubbles’ landing on the surface, stretching their membranes until they burst. Cicada wings use force to render the bacteria useless, which means that they don’t develop resistance or become harder to treat. This simple mechanism could be used to kill common bacteria that plague hospitals, like E. coli.

Cicada wing
Cicada wing. Image credit: Mathew Wills

Mimicking cicada wings to create smart surfaces

Scientists have been working to synthesize biodegradable polymers that mimic the ripple effect of cicada wings. Materials such as clingfilm-like sustainable polymers can be stretched and relaxed in specific directions to create tiny spikes in the structure, on the nano and micro scale. This new technique is also inexpensive in comparison to other methods that generate complex patterns on polymers. And because it can be easily scaled up, it also has a potential use as self-cleaning surfaces in hospitals.

On the left: image of a cicada. On the right: zoomed-in image of cicada wing surface showing nano structures.
Nano structures on cicada wing.Image credit: Zhang et al. Cicada Wings A Stamp from Nature for Nanoimprint Lithography. Small 2006 2 12 1440 1443.

Materials science inspired by nature

Apart from tackling hospital infections, this antimicrobial technology has potential impact in various other industries and applications, from door handles to food packaging. In fact, you could soon have this cicada-inspired molecular engineering inside you, as part of an implant!

Cicada wings themselves hold more secrets, with thrilling implications for material science. Their waxy coating has ‘super-hydrophobicity’ properties, repelling water into droplets and making cicadas self-cleaning. In addition, cicada wings are anti-reflective allowing them to camouflage -explaining why you can hear them but never see them at night -, a property which could be harnessed into solar cell technology.

Water droplets on cicada wing highlighting the hydrophobic properties.
Water droplets on cicada wing highlighting the hydrophobic properties. Image credit: Kaitlyn Melton _ Flickr

More research in this area will show how effective cicada wing-inspired materials are for a wide variety of applications. For now, we are looking forward to this amazing technology becoming incorporated into everyday life.

Giving textile waste and dyes a second chance

Following on our blogs exploring circular economy and zero waste, we welcome our new guest blogger, Dr. Antonio Ovejero-Perez. A postdoc from the Department of Chemical Engineering, Antonio’s research is focused on extracting dyes from textiles waste. 

Who hasn’t heard a family member say: “Back in the day, I only got new clothing for Christmas or birthday”? Now, in our fast-paced world things have changed. How many times a year do we buy clothes? Trends come and go quickly, and “fast fashion” has become more and more popular. 

But what is it? Fast fashion refers to the rapid production and consumption of inexpensive clothing items, often imitating current trends from the catwalk or celebrity culture. It prioritizes speed and affordability, resulting in frequent turnover of collections and low-cost garments. The New York Times first used the term to describe Zara’s mission to have garments in stores for just 15 days. This model involves design, production, and rapid distribution. Fast fashion creates large quantities of garments in very short periods of time at a low price.

Growth of clothing sales and decline in clothing utilisation since 2000.
Growth of clothing sales and decline in clothing utilisation since 2000. Source: Euromonitor International Apparel & Footwear 2016 Edition; World Bank, World development indicators – GD (2017)

This system encourages excessive consumption and clothes are used fewer times due to the social pressure of fashion trends. In addition, the consumer normally prefers to spend less money and change styles more often rather than buying more expensive garments that last long but will fall quickly out of popularity.

Fast fashion environmental consequences

The problem lies in the rapid production of garments. It is estimated that 92 million tonnes of textile waste are produced every year, expected to reach 34 million tonnes by 2030. The presence of dyes in the fabrics and the need for homogeneous input for fibre recycling complicates its recycling. Currently, textile waste is either incinerated or landfilled. Nowadays, recycled plastic bottles are the only source of recycled polyester for garment production, rather than recycled clothing. Thus, new raw materials are used for textile production: cotton (2.5% of farmland) and synthetic materials like polyester (342 million barrels of oil annually), driving environmental impact.

 

Image of mountains of clothes from waste generated by the textile and clothing industry
Textile waste generated by the clothing industry as a consequence of fast fashion. Source: University of Queensland.

But textile waste accumulation is not the only problem of the fast fashion industry. The excessive demand of clothing requires huge amounts of energy that, normally, come from non-renewable sources. The textile and fashion industry accounts for a 10% of global carbon emissions, more than the aviation and shipping sectors combined. Water consumption is also substantial, accounting for 20% of global wastewater production per year. In addition, the textile dyeing part of the process uses 43 million tonnes of chemicals a year.

Tackling the fast fashion problem

But is it all the consumer’s fault? Consumers do have responsibility and the chance to change habits to put pressure on retailers. But the textile industry also needs to change, producing clothes more sustainably and reusing both dyes and textiles. As previously mentioned, textile recycling is limited by the presence of dyes; thus, technologies that are able to recover dyes from textiles are needed. However, making that in a sustainable way is not easy.

Recovering dyes from textile waste to be reused

In this sense, in our group, and in one of the startups founded in our group, DyeRecycle Ltd., we use a low-cost green solvent to selectively extract dyes from fabric wastes, enabling circular economy. Using this method, we can recover a decoloured polyester fabric with intact properties for mechanical and chemical recyclers. In addition, the dye-rich green solvent can be used as a dye bath to dye new garments, or be recovered and sold, as it comes unaltered out of the process. This way, our technology tackles textile accumulation and chemicals and water usage problems in one solution.

Textiles samples coloured by using recycled dyes.
Textiles samples coloured by using recycled dyes. Source: DyeRecycle LtD.

Interdisciplinary education leads to increased earnings

“Greater exposure to interdisciplinarity—especially for science majors—is associated with increased earnings after college graduation.” This is one of the conclusions of an article on interdisciplinary education by Han et al in the Proceedings of the National Academy of Sciences, published in 2023.

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Academic-industry partnerships: risk, money, ideas and skills

One of the fun things I have to do in my job is find ways to increase collaborative research between IMSE and commercial companies. This is complicated. Research is risky, it’s expensive, it’s built on constantly generating new ideas, and this only happens with the right mix of the right people. How can we make all of this happen? One of the ways is with big collaborative research projects which are part-funded by industry and partly by public investment. In this post, I look at how this works.

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The next generation: tech, people and skills

It may sound like a cliché these days to hear people describe some new piece of technology as ‘next generation’. But here at IMSE, we’re working on the convergent science that underpins those kinds of technologies. And on our Master’s course, we’re training the people who will invent and develop these next generation technologies, and the manufacturing processes for them too. On 23rd June this year, we got to hear from our current cohort of 12 MRes students about progress on their research projects. It’s a great day for IMSE every year to see our students putting the IMSE approach into practice!

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