Tag Archives: Tawfique Hasan

‘SWEET’ (smart, wearable, and eco-friendly electronic textiles)

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I always appreciate a good acronym and this one is pretty good. (From my perspective, a good acronym is memorable and doesn’t involve tortured terminology such as CRISPR-Cas9, which stands for clustered regularly interspaced short palindromic repeats-CRISPR-associated protein 9).

On to ‘SWEET’ and a January 2, 2025 news item on ScienceDaily announcing a new UK study on wearable e-textiles,

A research team led by the University of Southampton and UWE Bristol [University of the West of England Bristol] has shown wearable electronic textiles (e-textiles) can be both sustainable and biodegradable.

A new study, which also involved the universities of Exeter, Cambridge, Leeds and Bath, describes and tests a new sustainable approach for fully inkjet-printed, eco-friendly e-textiles named ‘Smart, Wearable, and Eco-friendly Electronic Textiles’, or ‘SWEET’.

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A January 2, 2025 University of Southampton press release (also on EurekAlert), which originated the news item, describes e-textiles and how this latest work represents a step forward in making them environmentally friendly,

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E-textiles are those with embedded electrical components, such as sensors, batteries or lights. They might be used in fashion, for performance sportwear, or for medical purposes as garments that monitor people’s vital signs.

Such textiles need to be durable, safe to wear and comfortable, but also, in an industry which is increasingly concerned with clothing waste, they need to be kind to the environment when no longer required.

Professor Nazmul Karim at the University of Southampton’s Winchester School of Art, who led the study, explains: “Integrating electrical components into conventional textiles complicates the recycling of the material because it often contains metals, such as silver, that don’t easily biodegrade. Our potential ecofriendly approach for selecting sustainable materials and manufacturing overcomes this, enabling the fabric to decompose when it is disposed of.”

The team’s design has three layers, a sensing layer, a layer to interface with the sensors and a base fabric. It uses a textile called Tencel for the base, which is made from renewable wood and is biodegradable. The active electronics in the design are made from graphene, along with a polymer called PEDOT: PSS. These conductive materials are precision inkjet-printed onto the fabric.

The researchers tested samples of the material for continuous monitoring of human physiology using five volunteers. Swatches of the fabric, connected to monitoring equipment, were attached to gloves worn by the participants. Results confirmed the material can effectively and reliably measure both heart rate and temperature at the industry standard level.

Dr Shaila Afroj, an Associate Professor of Sustainable Materials from the University of Exeter and a co-author of the study, highlighted the importance of this performance: “Achieving reliable, industry-standard monitoring with eco-friendly materials is a significant milestone. It demonstrates that sustainability doesn’t have to come at the cost of functionality, especially in critical applications like healthcare.”

The project team then buried the e-textiles in soil to measure its biodegradable properties. After four months, the fabric had lost 48 percent of its weight and 98 percent of its strength, suggesting relatively rapid and also effective decomposition. Furthermore, a life cycle assessment revealed the graphene-based electrodes had up to 40 times less impact on the environment than standard electrodes.

Marzia Dulal from UWE Bristol, a Commonwealth PhD Scholar and the first author of the study, highlighted the environmental impact: “Our life cycle analysis shows that graphene-based e-textiles have a fraction of the environmental footprint compared to traditional electronics. This makes them a more responsible choice for industries looking to reduce their ecological impact.”

The ink-jet printing process is also a more sustainable approach for e-textile fabrications, depositing exact numbers of functional materials on textiles as needed, with almost no material waste and less use of water and energy than conventional screen printing.

Professor Karim concludes: “ Amid rising pollution from landfill sites, our study helps to address a lack of research in the area of biodegradation of e-textiles. These materials will become increasingly more important in our lives, particularly in the area of healthcare, so it’s really important we consider how to make them more eco-friendly, both in their manufacturing and disposal.”

The researchers hope they can now move forward with designing wearable garments made from SWEET for potential use in the healthcare sector, particularly in the area of early detection and prevention of heart-related diseases that 640 million people (source: BHF [British Heart Foundation]) suffer from worldwide.

Here’s a link to and a citation for the paper,

Sustainable, Wearable, and Eco-Friendly Electronic Textiles by Marzia Dulal, Harsh Rajesh Mansukhlal Modha, Jingqi Liu, Md Rashedul Islam, Chris Carr, Tawfique Hasan, Robin Michael Statham Thorn, Shaila Afroj, Nazmul Karim. Energy & Enviornmental Materials DOI: https://doi.org/10.1002/eem2.12854 First published: 18 December 2024

This paper is open access.

‘Frozen smoke’ sensors can detect toxic formaldehyde in homes and offices

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I love the fact that ‘frozen smoke’ is another term for aerogel (which has multiple alternative terms) and the latest work on this interesting material is from the University of Cambridge (UK) according to a February 9, 2023 news item on ScienceDaily,

Researchers have developed a sensor made from ‘frozen smoke’ that uses artificial intelligence techniques to detect formaldehyde in real time at concentrations as low as eight parts per billion, far beyond the sensitivity of most indoor air quality sensors.

The researchers, from the University of Cambridge, developed sensors made from highly porous materials known as aerogels. By precisely engineering the shape of the holes in the aerogels, the sensors were able to detect the fingerprint of formaldehyde, a common indoor air pollutant, at room temperature.

The proof-of-concept sensors, which require minimal power, could be adapted to detect a wide range of hazardous gases, and could also be miniaturised for wearable and healthcare applications. The results are reported in the journal Science Advances.

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A February 9, 2024 University of Cambridge press release (also on EurekAlert), which originated the news item, describes the problem and the proposed solution in more detail, Note: Links have been removed,

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Volatile organic compounds (VOCs) are a major source of indoor air pollution, causing watery eyes, burning in the eyes and throat, and difficulty breathing at elevated levels. High concentrations can trigger attacks in people with asthma, and prolonged exposure may cause certain cancers.

Formaldehyde is a common VOC and is emitted by household items including pressed wood products (such as MDF), wallpapers and paints, and some synthetic fabrics. For the most part, the levels of formaldehyde emitted by these items are low, but levels can build up over time, especially in garages where paints and other formaldehyde-emitting products are more likely to be stored.

According to a 2019 report from the campaign group Clean Air Day, a fifth of households in the UK showed notable concentrations of formaldehyde, with 13% of residences surpassing the recommended limit set by the World Health Organization (WHO).

“VOCs such as formaldehyde can lead to serious health problems with prolonged exposure even at low concentrations, but current sensors don’t have the sensitivity or selectivity to distinguish between VOCs that have different impacts on health,” said Professor Tawfique Hasan from the Cambridge Graphene Centre, who led the research.

“We wanted to develop a sensor that is small and doesn’t use much power, but can selectively detect formaldehyde at low concentrations,” said Zhuo Chen, the paper’s first author.

The researchers based their sensors on aerogels: ultra-light materials sometimes referred to as ‘liquid smoke’, since they are more than 99% air by volume. The open structure of aerogels allows gases to easily move in and out. By precisely engineering the shape, or morphology, of the holes, the aerogels can act as highly effective sensors.

Working with colleagues at Warwick University, the Cambridge researchers optimised the composition and structure of the aerogels to increase their sensitivity to formaldehyde, making them into filaments about three times the width of a human hair. The researchers 3D printed lines of a paste made from graphene, a two-dimensional form of carbon, and then freeze-dried the graphene paste to form the holes in the final aerogel structure. The aerogels also incorporate tiny semiconductors known as quantum dots.

The sensors they developed were able to detect formaldehyde at concentrations as low as eight parts per billion, which is 0.4 percent of the level deemed safe in UK workplaces. The sensors also work at room temperature, consuming very low power.

“Traditional gas sensors need to be heated up, but because of the way we’ve engineered the materials, our sensors work incredibly well at room temperature, so they use between 10 and 100 times less power than other sensors,” said Chen.

To improve selectivity, the researchers then incorporated machine learning algorithms into the sensors. The algorithms were trained to detect the ‘fingerprint’ of different gases, so that the sensor was able to distinguish the fingerprint of formaldehyde from other VOCs.

“Existing VOC detectors are blunt instruments – you only get one number for the overall concentration in the air,” said Hasan. “By building a sensor that is able to detect specific VOCs at very low concentrations in real time, it can give home and business owners a more accurate picture of air quality and any potential health risks.”

The researchers say that the same technique could be used to develop sensors to detect other VOCs. In theory, a device the size of a standard household carbon monoxide detector could incorporate multiple different sensors within it, providing real-time information about a range of different hazardous gases. The team at Warwick are developing a low-cost multi-sensor platform that will incorporate these new aerogel materials and, coupled with AI algorithms, detect different VOCs.

“By using highly porous materials as the sensing element, we’re opening up whole new ways of detecting hazardous materials in our environment,” said Chen.

The research was supported in part by the Henry Royce Institute, and the Engineering and Physical Sciences Research Council (EPSRC), part of UK Research and Innovation (UKRI). Tawfique Hasan is a Fellow of Churchill College, Cambridge.

Here’s a link to and a citation for the paper,

Real-time, noise and drift resilient formaldehyde sensing at room temperature with aerogel filaments by Zhuo Chen, Binghan Zhou, Mingfei Xiao, Tynee Bhowmick, Padmanathan Karthick Kannan, Luigi G. Occhipinti, Julian William Gardner, and Tawfique Hasan. Science Advances 9 Feb 2024 Vol 10, Issue 6 DOI: 10.1126/sciadv.adk6856

This paper is open access.

University of Cambridge makes waves with graphene piano

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The news about the graphene piano (and anti-fraud lasers, etc.) is contained in a report from the University of Cambridge’s Cambridge Innovation and Knowledge Centre (CIKC), according to a Nov. 5, 2013 news item on phys.org (Note: A link has been removed),

Two prototypes – a detection device which users lasers to fight fraud, and a piano which demonstrates the potential of printed electronics – have been unveiled by Cambridge researchers.

A detection device which uses printed lasers to identify counterfeit goods has been developed by researchers, who say that it could help to make products more resistant to fraud.

The detector is one of a number of innovations covered in a new report by the Cambridge Innovation and Knowledge Centre (CIKC), which has been developing advanced manufacturing technologies for photonics and electronics.

The same document also outlines a new method for printing graphene, showing how the one atom-thick material could be used to make cheap, printed electronics. Using a graphene-based ink, researchers have demonstrated this by creating a transparent, flexible piano.

Here’s a video about the transparent piano produced at Cambridge,

The Nov. 5, 2013 University of Cambridge news release, which originated the news item, offers details about the piano and the graphene inks used to produce it,

The printed piano meanwhile demonstrates the potential of using graphene in real applications where printed electronics might be needed – such as heart monitors and other sensors.

The research team behind it, Drs Tawfique Hasan, Felice Torrisi and Prof Andrea Ferrari, at the Cambridge Graphene Centre, have developed a graphene-based ink. Like the material itself, this has a number of interesting properties, including flexibility, optical transparency, and electrical conductivity.

Other conductive inks are made from precious metals such as silver, which makes them very expensive to produce and process, whereas graphene is both cheap, environmentally stable, and does not require much processing after printing. Graphene ink is also superior to conductive polymers in terms of cost, stability and performance.

The piano, designed in collaboration with Novalia Limited, shows off the graphene ink’s potential. The keys of the transparent piano are made from graphene-based inks, which have been printed on to a plastic film. These keys, working as electrodes, are connected to a simple electronic circuit-board, a battery and speaker. When a person touches a graphene electrode, the amount of electrical charge held in the key changes. This is then detected and redirected by the circuit to the speaker, creating the musical note.

The same research team, in collaboration with Printed Electronics Limited, has developed a flexible prototype digital display. This display uses conventional printable materials, but with a transparent, electrically conductive graphene layer on top. The graphene layer is not only a flexible but also more conductive and transparent than the conventional polymer it replaces. These simple displays can be used in a wide range of smart packaging applications such as toys, labelling and board games.

“Both of these devices show how graphene could be printed on to a whole range of surfaces, which makes it ideal for printed electronics,” Dr Hasan, the lead researcher behind the prototypes, said. For example, it might eventually be possible to print electronics on to clothing and to make wearable patches to monitor people with health conditions, such as a heart problem.”

Another potential application is cheap, printable sensors, which could be used to track luggage around an airport to ensure it is loaded on to the correct plane, or to follow products across a production and supply chain.

For anyone who’d like to see the report and get information on the other projects discussed in it just click on the title: Advanced Manufacturing Technologies for Photonics and Electronics – Exploiting Molecular and Macromolecular Materials: Final Report.

*’Unviersity in headline changed to University 11:11 am PDT Nov. 7, 2013.