Tag Archives: Imperial College London (ICL)

Smart City tech brief: facial recognition, cybersecurity; privacy protection; and transparency

This May 10, 2022 Association for Computing Machinery (ACM) announcement (received via email) has an eye-catching head,

Should Smart Cities Adopt Facial Recognition, Remote Monitoring Software+Social Media to Police [verb] Info?

The Association for Computing Machinery, the largest and most prestigious computer science society worldwide (100,000 members) has released a report, ACM TechBrief: Smart Cities, for smart city planners to address 1) cybersecurity; 2) privacy protections; 3) fairness and transparency; and 4) sustainability when planning and designing systems, including climate impact. 

There’s a May 3, 2022 ACM news release about the latest technical brief,

The Association for Computing Machinery’s global Technology Policy Council (ACM TPC) just released, “ACM TechBrief: Smart Cities,” which highlights the challenges involved in deploying information and communication technology to create smart cities and calls for policy leaders planning such projects to do so without compromising security, privacy, fairness and sustainability. The TechBrief includes a primer on smart cities, key statistics about the growth and use of these technologies, and a short list of important policy implications.

“Smart cities” are municipalities that use a network of physical devices and computer technologies to make the delivery of public services more efficient and/or more environmentally friendly. Examples of smart city applications include using sensors to turn off streetlights when no one is present, monitoring traffic patterns to reduce roadway congestion and air pollution, or keeping track of home-bound medical patients in order to dispatch emergency responders when needed. Smart cities are an outgrowth of the Internet of Things (IoT), the rapidly growing infrastructure of literally billions of physical devices embedded with sensors that are connected to computers and the Internet.

The deployment of smart city technology is growing across the world, and these technologies offer significant benefits. For example, the TechBrief notes that “investing in smart cities could contribute significantly to achieving greenhouse gas emissions reduction targets,” and that “smart cities use digital innovation to make urban service delivery more efficient.”

Because of the meteoric growth and clear benefits of smart city technologies, the TechBrief notes that now is an urgent time to address some of the important public policy concerns that smart city technologies raise. The TechBrief lists four key policy implications that government officials, as well as the private companies that develop these technologies, should consider.

These include:

Cybersecurity risks must be considered at every stage of every smart city technology’s life cycle.

Effective privacy protection mechanisms must be an essential component of any smart city technology deployed.

Such mechanisms should be transparently fair to all city users, not just residents.

The climate impact of smart city infrastructures must be fully understood as they are being designed and regularly assessed after they are deployed

“Smart cities are fast becoming a reality around the world,”explains Chris Hankin, a Professor at Imperial College London and lead author of the ACM TechBrief on Smart Cities. “By 2025, 26% of all internet-connected devices will be used in a smart city application. As technologists, we feel we have a responsibility to raise important questions to ensure that these technologies best serve the public interest. For example, many people are unaware that some smart city technologies involve the collection of personally identifiable data. We developed this TechBrief to familiarize the public and lawmakers with this topic and present some key issues for consideration. Our overarching goal is to guide enlightened public policy in this area.”

“Our new TechBrief series builds on earlier and ongoing work by ACM’s technology policy committees,” added James Hendler, Professor at Rensselaer Polytechnic Institute and Chair of the ACM Technology Policy Council. “Because many smart city applications involve algorithms making decisions which impact people directly, this TechBrief calls for methods to ensure fairness and transparency in how these systems are developed. This reinforces an earlier statement we issued that outlined seven principles for algorithmic transparency and accountability. We also note that smart city infrastructures are especially vulnerable to malicious attacks.”

This TechBrief is the third in a series of short technical bulletins by ACM TPC that present scientifically grounded perspectives on the impact of specific developments or applications of technology. Designed to complement ACM’s activities in the policy arena, TechBriefs aim to inform policymakers, the public, and others about the nature and implications of information technologies. The first ACM TechBrief focused on climate change, while the second addressed facial recognition. Topics under consideration for future issues include quantum computing, election security, and encryption.

About the ACM Technology Policy Council

ACM’s global Technology Policy Council sets the agenda for ACM’s global policy activities and serves as the central convening point for ACM’s interactions with government organizations, the computing community, and the public in all matters of public policy related to computing and information technology. The Council’s members are drawn from ACM’s global membership. It coordinates the activities of ACM’s regional technology policy groups and sets the agenda for global initiatives to address evolving technology policy issues.

About ACM

ACM, the Association for Computing Machinery, is the world’s largest educational and scientific computing society, uniting educators, researchers and professionals to inspire dialogue, share resources and address the field’s challenges. ACM strengthens the computing profession’s collective voice through strong leadership, promotion of the highest standards, and recognition of technical excellence. ACM supports the professional growth of its members by providing opportunities for life-long learning, career development, and professional networking.

This is indeed a brief. I recommend reading it as it provides a very good overview to the topic of ‘smart cities’ and raises a question or two. For example, there’s this passage from the April 2022 Issue 3 Technical Brief on p. 2,

… policy makers should target broad and fair access and application of AI and, in general, ICT [information and communication technologies]. This can be achieved through transparent planning and decision-making processes for smart city infrastructure and application developments, such as open hearings, focus groups, and advisory panels. The goal must be to minimize potential harm while maximizing the benefits that algorithmic decision-making [emphasis mine] can bring

Is this algorithmic decision-making under human supervision? It doesn’t seem to be specified in the brief itself. It’s possible the answer lies elsewhere. After all, this is the third in the series.

Tiny nanomagnets interact like neurons in the brain for low energy artificial intelligence (brainlike) computing

Saving energy is one of the main drivers for the current race to make neuromorphic (brainlike) computers as this May 5, 2022 news item on Nanowerk comments, Note: Links have been removed,

Researchers have shown it is possible to perform artificial intelligence using tiny nanomagnets that interact like neurons in the brain.

The new method, developed by a team led by Imperial College London researchers, could slash the energy cost of artificial intelligence (AI), which is currently doubling globally every 3.5 months. [emphasis mine]

In a paper published in Nature Nanotechnology (“Reconfigurable training and reservoir computing in an artificial spin-vortex ice via spin-wave fingerprinting”), the international team have produced the first proof that networks of nanomagnets can be used to perform AI-like processing. The researchers showed nanomagnets can be used for ‘time-series prediction’ tasks, such as predicting and regulating insulin levels in diabetic patients.

A May 5, 2022 Imperial College London (ICL) press release (also on EurekAlert) by Hayley Dunning, which originated the news item delves further into the research,

Artificial intelligence that uses ‘neural networks’ aims to replicate the way parts of the brain work, where neurons talk to each other to process and retain information. A lot of the maths used to power neural networks was originally invented by physicists to describe the way magnets interact, but at the time it was too difficult to use magnets directly as researchers didn’t know how to put data in and get information out.

Instead, software run on traditional silicon-based computers was used to simulate the magnet interactions, in turn simulating the brain. Now, the team have been able to use the magnets themselves to process and store data – cutting out the middleman of the software simulation and potentially offering enormous energy savings.

Nanomagnetic states

Nanomagnets can come in various ‘states’, depending on their direction. Applying a magnetic field to a network of nanomagnets changes the state of the magnets based on the properties of the input field, but also on the states of surrounding magnets.

The team, led by Imperial Department of Physics researchers, were then able to design a technique to count the number of magnets in each state once the field has passed through, giving the ‘answer’.

Co-first author of the study Dr Jack Gartside said: “We’ve been trying to crack the problem of how to input data, ask a question, and get an answer out of magnetic computing for a long time. Now we’ve proven it can be done, it paves the way for getting rid of the computer software that does the energy-intensive simulation.”

Co-first author Kilian Stenning added: “How the magnets interact gives us all the information we need; the laws of physics themselves become the computer.”

Team leader Dr Will Branford said: “It has been a long-term goal to realise computer hardware inspired by the software algorithms of Sherrington and Kirkpatrick. It was not possible using the spins on atoms in conventional magnets, but by scaling up the spins into nanopatterned arrays we have been able to achieve the necessary control and readout.”

Slashing energy cost

AI is now used in a range of contexts, from voice recognition to self-driving cars. But training AI to do even relatively simple tasks can take huge amounts of energy. For example, training AI to solve a Rubik’s cube took the energy equivalent of two nuclear power stations running for an hour.

Much of the energy used to achieve this in conventional, silicon-chip computers is wasted in inefficient transport of electrons during processing and memory storage. Nanomagnets however don’t rely on the physical transport of particles like electrons, but instead process and transfer information in the form of a ‘magnon’ wave, where each magnet affects the state of neighbouring magnets.

This means much less energy is lost, and that the processing and storage of information can be done together, rather than being separate processes as in conventional computers. This innovation could make nanomagnetic computing up to 100,000 times more efficient than conventional computing.

AI at the edge

The team will next teach the system using real-world data, such as ECG signals, and hope to make it into a real computing device. Eventually, magnetic systems could be integrated into conventional computers to improve energy efficiency for intense processing tasks.

Their energy efficiency also means they could feasibly be powered by renewable energy, and used to do ‘AI at the edge’ – processing the data where it is being collected, such as weather stations in Antarctica, rather than sending it back to large data centres.

It also means they could be used on wearable devices to process biometric data on the body, such as predicting and regulating insulin levels for diabetic people or detecting abnormal heartbeats.

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

Reconfigurable training and reservoir computing in an artificial spin-vortex ice via spin-wave fingerprinting by Jack C. Gartside, Kilian D. Stenning, Alex Vanstone, Holly H. Holder, Daan M. Arroo, Troy Dion, Francesco Caravelli, Hidekazu Kurebayashi & Will R. Branford. Nature Nanotechnology (2022) DOI: https://doi.org/10.1038/s41565-022-01091-7 Published 05 May 2022

This paper is behind a paywall.

Spiky materials that can pop bacteria?

Bacteria interacting with four different topographies Courtesy: Imperial College London

A February 9, 2022 news item on phys.org describes some bioinspired research that could help cut down on the use of disinfectants,

Researchers have created intricately patterned materials that mimic antimicrobial, adhesive and drag reducing properties found in natural surfaces.

The team from Imperial College London found inspiration in the wavy and spiky surfaces found in insects, including on cicada and dragonfly wings, which ward off bacteria.

They hope the new materials could be used to create self-disinfecting surfaces and offer an alternative to chemically functionalized surfaces and cleaners, which can promote the growth of antibiotic-resistant bacteria.

A February 9, 2022 Imperial College London (ICL) press release by Caroline Brogan, which originated the news item, describes the work in more technical detail,

The tiny waves, which overlap at defined angles to create spikes and ripples, could also help to reduce drag on marine transport by mimicking shark skin, and to enhance the vibrancy of color without needing pigment, by mimicking insects.

Senior author Professor Joao Cabral, of Imperial’s Department of Chemical Engineering, said, “It’s inspiring to see in miniscule detail how the wings and skins of animals help them master their environments. Animals evolved wavy surfaces to kill bacteria, enhance color, and reduce drag while moving through water. We’re borrowing these natural tricks for the very same purposes, using a trick reminiscent of a Fourier wave superposition.”

Spiky structures

Researchers created the new materials by stretching and compressing a thin, soft, sustainable plastic resembling clingfilm to create three-dimensional nano- and microscale wavy patterns, compatible with sustainable and biodegradable polymers. 

The spiky structure was inspired by the way insects and fish have evolved to interact with their environments. The corrugated ripple effect is seen in the wings of cicadas and dragonflies, whose surfaces are made of tiny spikes which pop bacterial cells to keep the insects clean.  

The structure could also be applied to ships to reduce drag and boost efficiency – an application inspired by shark skin, which contains nanoscale horizontal ridges to reduce friction and drag.

Another application is in producing vibrant colours like those seen in the wings of morpho blue butterflies, whose cells are arranged to reflect and bend light into a brilliant blue without using pigment. Known as structural colour, other examples include the blue in peacock feathers, the shells of iridescent beetles, and blue human eyes.

Scaling up waves

To conduct the research, which is published in Physical Review Letters, the researchers studied specimens of cicadas and dragonflies from the Natural History Museum, and sedimentary deposits and rock formations documented by Trinity College Dublin.

They discovered that they could recreate these naturally occurring surface waves by stretching and then relaxing thin polymer skins in precise directions at the nanoscale.

While complex patterns can be fabricated by lithography and other methods, for instance in silicon microchip production, these are generally prohibitively expensive to use over large areas. This new technique, on the other hand, is ready to be scaled up relatively inexpensively if confirmed to be effective and robust. 

Potential applications include self-disinfecting surfaces in hospitals, schools, public transport, and food manufacturing. They could even help keep medical implants clean, which is important as these can host networks of bacterial matter known as biofilms that are notoriously difficult to kill. 

Naturally occurring wave patterns are also seen in the wrinkling of the human brain and fingertips as well as the ripples in sand beds. First author Dr Luca Pellegrino from the Department of Chemical Engineering, said: “The idea is compelling because it is simple: by mimicking the surface waves found in nature, we can create a palette of patterns with important applications. Through this work we can also learn more about the possible origins of these natural forms – a field called morphogenesis.” 

he next focus for the team is to test the effectiveness and robustness of the material in real-world settings, like on bus surfaces. The researchers hope it can contribute to solutions to surface cleanliness that are not reliant on chemical cleaners. To this end, they have been awarded a €5.4million EU HORIZON grant with collaborators ranging from geneticists at KU Leuven to a bus manufacturer to develop sustainable and robust antimicrobial surfaces for high traffic contexts. 

Here’s a link (the press release also has a link) to and a citation for the paper,

Ripple Patterns Spontaneously Emerge through Sequential Wrinkling Interference in Polymer Bilayers by Luca Pellegrino, Annabelle Tan, and João T. Cabral. Phys. Rev. Lett. 128, 058001 Vol. 128, Issue 5 — 4 February 2022 Published online 2 February 2022

This paper is behind a paywall.

This work reminds me of Sharklet, a company that was going to produce materials that mimicked the structure of sharkskin. Apparently, sharks have nanostructures on their skin which prevents bacteria and more from finding a home there.

The how and why of nanopores

An August 19, 2021 Universidade NOVA de Lisboa ITQB NOVA press release (also on EurekAlert) explains what nanopores are while describing research into determining how their locations can be controlled,

At the simplest of levels, nanopores are (nanometre-sized) holes in an insulating membrane. The hole allows ions to pass through the membrane when a voltage is applied, resulting in a measurable current. When a molecule passes through a nanopore it causes a change in the current, this can be used to characterize and even identify individual molecules. Nanopores are extremely powerful single-molecule biosensing devices and can be used to detect and sequence DNA, RNA, and even proteins. Recently, it has been used in the SARS-CoV-2 virus sequencing.  

Solid-state nanopores are an extremely versatile type of nanopore formed in ultrathin membranes (less than 50 nanometres), made from materials such as silicon nitride (SiNx). Solid-state nanopores can be created with a range of diameters and can withstand a multitude of conditions (discover more about solid-state nanopore fabrication techniques here). One of the most appealing techniques with which to fabricate nanopores is Controlled Breakdown (CBD). This technique is quick, reduces fabrication costs, does not require specialized equipment, and can be automated.

CBD is a technique in which an electric field is applied across the membrane to induce a current. At some point, a spike in the current is observed, signifying pore formation. The voltage is then quickly reduced to ensure the fabrication of a single, small nanopore.

The mechanisms underlying this process have not been fully elucidated thus an international team involving ITQB NOVA decided to further investigate how electrical conduction through the membrane occurs during breakdown, namely how oxidation and reduction reactions (also called redox reactions, they imply electron loss or gain, respectively) influence the process. To do this, the team created three devices in which the electric field is applied to the membrane (a silicon-rich SiNx membrane) in different ways: via metal electrodes on both sides of the membrane; via electrolyte solutions on both sides of the membrane; and via a mixed device with a metal electrode on one side and an electrolyte solution on the other.

Results showed that redox reactions must occur at the membrane-electrolyte interface, whilst the metal electrodes circumvent this need. The team also demonstrated that, because of this phenomenon, nanopore fabrication could be localized to certain regions by performing CBD with metal microelectrodes on the membrane surface. Finally, by varying the content of silicon in the membrane, the investigators demonstrated that conduction and nanopore formation is highly dependent on the membrane material since it limits the electrical current in the membrane.

“Controlling the location of nanopores has been of interest to us for a number of years”, says James Yates. Pedro Sousa adds that “our findings suggest that CBD can be used to integrate pores with complementary micro or nanostructures, such as tunneling electrodes or field-effect sensors, across a range of different membrane materials.”  These devices may then be used for the detection of specific molecules, such as proteins, DNA, or antibodies, and applied to a wide array of scenarios, including pandemic surveillance or food safety.

This project was developed by a research team led by ITQB NOVA’s James Yates and has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No 724300 and 875525). Co-author Pedro Miguel Sousa is also from ITQB NOVA. The other consortium members are from the University of Oxford, Oak Ridge National Laboratory, Imperial College London and Queen Mary University of London. The authors would like to thank Andrew Briggs for providing financial support.

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

Understanding Electrical Conduction and Nanopore Formation During Controlled Breakdown by Jasper P. Fried, Jacob L. Swett, Binoy Paulose Nadappuram, Aleksandra Fedosyuk, Pedro Miguel Sousa, Dayrl P. Briggs, Aleksandar P. Ivanov, Joshua B. Edel, Jan A. Mol, James R. Yates. Small DOI: https://doi.org/10.1002/smll.202102543 First published: 01 August 2021

This paper is open access.

Your cyborg future (brain-computer interface) is closer than you think

Researchers at the Imperial College London (ICL) are warning that brain-computer interfaces (BCIs) may pose a number of quandaries. (At the end of this post, I have a little look into some of the BCI ethical issues previously explored on this blog.)

Here’s more from a July 20, 2021American Institute of Physics (AIP) news release (also on EurekAlert),

Surpassing the biological limitations of the brain and using one’s mind to interact with and control external electronic devices may sound like the distant cyborg future, but it could come sooner than we think.

Researchers from Imperial College London conducted a review of modern commercial brain-computer interface (BCI) devices, and they discuss the primary technological limitations and humanitarian concerns of these devices in APL Bioengineering, from AIP Publishing.

The most promising method to achieve real-world BCI applications is through electroencephalography (EEG), a method of monitoring the brain noninvasively through its electrical activity. EEG-based BCIs, or eBCIs, will require a number of technological advances prior to widespread use, but more importantly, they will raise a variety of social, ethical, and legal concerns.

Though it is difficult to understand exactly what a user experiences when operating an external device with an eBCI, a few things are certain. For one, eBCIs can communicate both ways. This allows a person to control electronics, which is particularly useful for medical patients that need help controlling wheelchairs, for example, but also potentially changes the way the brain functions.

“For some of these patients, these devices become such an integrated part of themselves that they refuse to have them removed at the end of the clinical trial,” said Rylie Green, one of the authors. “It has become increasingly evident that neurotechnologies have the potential to profoundly shape our own human experience and sense of self.”

Aside from these potentially bleak mental and physiological side effects, intellectual property concerns are also an issue and may allow private companies that develop eBCI technologies to own users’ neural data.

“This is particularly worrisome, since neural data is often considered to be the most intimate and private information that could be associated with any given user,” said Roberto Portillo-Lara, another author. “This is mainly because, apart from its diagnostic value, EEG data could be used to infer emotional and cognitive states, which would provide unparalleled insight into user intentions, preferences, and emotions.”

As the availability of these platforms increases past medical treatment, disparities in access to these technologies may exacerbate existing social inequalities. For example, eBCIs can be used for cognitive enhancement and cause extreme imbalances in academic or professional successes and educational advancements.

“This bleak panorama brings forth an interesting dilemma about the role of policymakers in BCI commercialization,” Green said. “Should regulatory bodies intervene to prevent misuse and unequal access to neurotech? Should society follow instead the path taken by previous innovations, such as the internet or the smartphone, which originally targeted niche markets but are now commercialized on a global scale?”

She calls on global policymakers, neuroscientists, manufacturers, and potential users of these technologies to begin having these conversations early and collaborate to produce answers to these difficult moral questions.

“Despite the potential risks, the ability to integrate the sophistication of the human mind with the capabilities of modern technology constitutes an unprecedented scientific achievement, which is beginning to challenge our own preconceptions of what it is to be human,” [emphasis mine] Green said.

Caption: A schematic demonstrates the steps required for eBCI operation. EEG sensors acquire electrical signals from the brain, which are processed and outputted to control external devices. Credit: Portillo-Lara et al.

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

Mind the gap: State-of-the-art technologies and applications for EEG-based brain-computer interfaces by Roberto Portillo-Lara, Bogachan Tahirbegi, Christopher A.R. Chapman, Josef A. Goding, and Rylie A. Green. APL Bioengineering, Volume 5, Issue 3, , 031507 (2021) DOI: https://doi.org/10.1063/5.0047237 Published Online: 20 July 2021

This paper appears to be open access.

Back on September 17, 2020 I published a post about a brain implant and included some material I’d dug up on ethics and brain-computer interfaces and was most struck by one of the stories. Here’s the excerpt (which can be found under the “Brain-computer interfaces, symbiosis, and ethical issues” subhead): … From a July 24, 2019 article by Liam Drew for Nature Outlook: The brain,

“It becomes part of you,” Patient 6 said, describing the technology that enabled her, after 45 years of severe epilepsy, to halt her disabling seizures. Electrodes had been implanted on the surface of her brain that would send a signal to a hand-held device when they detected signs of impending epileptic activity. On hearing a warning from the device, Patient 6 knew to take a dose of medication to halt the coming seizure.

“You grow gradually into it and get used to it, so it then becomes a part of every day,” she told Frederic Gilbert, an ethicist who studies brain–computer interfaces (BCIs) at the University of Tasmania in Hobart, Australia. “It became me,” she said. [emphasis mine]

Gilbert was interviewing six people who had participated in the first clinical trial of a predictive BCI to help understand how living with a computer that monitors brain activity directly affects individuals psychologically1. Patient 6’s experience was extreme: Gilbert describes her relationship with her BCI as a “radical symbiosis”.

This is from another part of the September 17, 2020 posting,

… He [Gilbert] is now preparing a follow-up report on Patient 6. The company that implanted the device in her brain to help free her from seizures went bankrupt. The device had to be removed.

… Patient 6 cried as she told Gilbert about losing the device. … “I lost myself,” she said.

“It was more than a device,” Gilbert says. “The company owned the existence of this new person.”

It wasn’t my first thought when the topic of ethics and BCIs came up but as Gilbert’s research highlights: what happens if the company that made your implant and monitors it goes bankrupt?

If you have the time, do take a look at the entire entry under the “Brain-computer interfaces, symbiosis, and ethical issues” subhead of the September 17, 2020 posting or read the July 24, 2019 article by Liam Drew.

Should you have a problem finding the July 20, 2021 American Institute of Physics news release at either of the two links I have previously supplied, there’s a July 20, 2021 copy at SciTechDaily.com

Use kombucha to produce bacterial cellulose

The combination of the US Army, bacterial cellulose, and kombucha seems a little unusual. However, this January 26, 2021 U.S. Army Research Laboratory news release (also on EurekAlert) provides some clues as to how this combination makes sense,

Kombucha tea, a trendy fermented beverage, inspired researchers to develop a new way to generate tough, functional materials using a mixture of bacteria and yeast similar to the kombucha mother used to ferment tea.

With Army funding, using this mixture, also called a SCOBY, or symbiotic culture of bacteria and yeast, engineers at MIT [Massachusetts Institute of Technology] and Imperial College London produced cellulose embedded with enzymes that can perform a variety of functions, such as sensing environmental pollutants and self-healing materials.

The team also showed that they could incorporate yeast directly into the cellulose, creating living materials that could be used to purify water for Soldiers in the field or make smart packaging materials that can detect damage.

“This work provides insights into how synthetic biology approaches can harness the design of biotic-abiotic interfaces with biological organization over multiple length scales,” said Dr. Dawanne Poree, program manager, Army Research Office, an element of the U.S. Army Combat Capabilities Development Command, now known as DEVCOM, Army Research Laboratory. “This is important to the Army as this can lead to new materials with potential applications in microbial fuel cells, sense and respond systems, and self-reporting and self-repairing materials.”

The research, published in Nature Materials was funded by ARO [Army Research Office] and the Army’s Institute for Soldier Nanotechnologies [ISN] at the Massachusetts Institute of Technology. The U.S. Army established the ISN in 2002 as an interdisciplinary research center devoted to dramatically improving the protection, survivability, and mission capabilities of the Soldier and Soldier-supporting platforms and systems.

“We foresee a future where diverse materials could be grown at home or in local production facilities, using biology rather than resource-intensive centralized manufacturing,” said Timothy Lu, an MIT associate professor of electrical engineering and computer science and of biological engineering.

Researchers produced cellulose embedded with enzymes, creating living materials that could be used to purify water for Soldiers in the field or make smart packaging materials that can detect damage. These fermentation factories, which usually contain one species of bacteria and one or more yeast species, produce ethanol, cellulose, and acetic acid that gives kombucha tea its distinctive flavor.

Most of the wild yeast strains used for fermentation are difficult to genetically modify, so the researchers replaced them with a strain of laboratory yeast called Saccharomyces cerevisiae. They combined the yeast with a type of bacteria called Komagataeibacter rhaeticus that their collaborators at Imperial College London had previously isolated from a kombucha mother. This species can produce large quantities of cellulose.

Because the researchers used a laboratory strain of yeast, they could engineer the cells to do any of the things that lab yeast can do, such as producing enzymes that glow in the dark, or sensing pollutants or pathogens in the environment. The yeast can also be programmed so that they can break down pollutants/pathogens after detecting them, which is highly relevant to Army for chem/bio defense applications.

“Our community believes that living materials could provide the most effective sensing of chem/bio warfare agents, especially those of unknown genetics and chemistry,” said Dr. Jim Burgess ISN program manager for ARO.

The bacteria in the culture produced large-scale quantities of tough cellulose that served as a scaffold. The researchers designed their system so that they can control whether the yeast themselves, or just the enzymes that they produce, are incorporated into the cellulose structure. It takes only a few days to grow the material, and if left long enough, it can thicken to occupy a space as large as a bathtub.

“We think this is a good system that is very cheap and very easy to make in very large quantities,” said MIT graduate student and the paper’s lead author, Tzu-Chieh Tang. To demonstrate the potential of their microbe culture, which they call Syn-SCOBY, the researchers created a material incorporating yeast that senses estradiol, which is sometimes found as an environmental pollutant. In another version, they used a strain of yeast that produces a glowing protein called luciferase when exposed to blue light. These yeasts could be swapped out for other strains that detect other pollutants, metals, or pathogens.

The researchers are now looking into using the Syn-SCOBY system for biomedical or food applications. For example, engineering the yeast cells to produce antimicrobials or proteins that could benefit human health.

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

Living materials with programmable functionalities grown from engineered microbial co-cultures by Charlie Gilbert, Tzu-Chieh Tang, Wolfgang Ott, Brandon A. Dorr, William M. Shaw, George L. Sun, Timothy K. Lu & Tom Ellis. Nature Materials (2021) DOI: https://doi.org/10.1038/s41563-020-00857-5 Published: 11 January 2021

This paper is behind a paywall.