My guest in this episode of the Physics World Weekly podcast is Marco Caffio, who is co-founder of iGii. The UK-based company has developed a porous 3D carbon nanomaterial called Gii, which it manufactures for a range of customers and applications.
Caffio describes Gii as a 3D version of graphene that delivers many of the useful electronic, structural and chemical properties of that 2D wonder material. Unlike graphene, which can be difficult to manufacture and integrate into devices, Caffio explains that Gii can be customized for use in practical technologies such as chemical sensors, batteries and heaters.
We also chat about the genesis of the company and Caffio offers career advice to physicists who are keen on working in the materials-technology sector.
This episode of the Physics World Weekly podcast features Yonatan Cohen, who is co-founder and chief technology officer of Quantum Machines.
The company was started in 2018 by three physicists from Israel’s Weizmann Institute. It develops control systems for quantum computers and has about 300 employees and 500 customers worldwide.
Cohen explains why hybrid quantum–classical control systems are increasing in importance as quantum computers scale-up to include more and more qubits. He also talks about Quantum Machines’ strategy to support a wide range of qubit types – including superconducting circuits, trapped ions, neutral atoms, spins and NV centres.
We chat about some of the company’s products and its collaborations with quantum-technology companies including Rigetti Computing and Diraq. Cohen also gives career advice for physicists who want to work in the quantum sector.
Peeing at the Grand Prix just got a lot more meaningful. In the latest episode of Physics World Stories, Lucy Bell-Reeves and Olivia Wilson, who work for the start-up NPK Recovery, based at the University of the West of England, explain how their mobile system upcycles urine into fertilizer, right where it’s produced.
The pair unpack the physics and chemistry behind their approach, contrasting it with the energy-intensive Haber-Bosch process, which converts natural gas into ammonia under extreme heat and pressure at centralized plants. With the UK importing 100% of its nitrogen, and recent global conflicts exposing the fragility of fertilizer supply chains, the case for local, circular alternatives is growing stronger.
Host Andrew Glester hears about the pair’s experience at the British Grand Prix in Silverstone, the UK’s leg of the Formula 1 World Championship. Bell-Reeves and Wilson reflect on what it’s like to experience the “Grand Pee”, and how attendees react when they discover where their urine ends up.
While not pitched as a replacement for industrial-scale ammonia production, the system offers a smart fix for off-grid sites facing sudden spikes in human waste.
Physicists (and engineers) are great at estimating. We’ve obviously never counted the number of electrons in the visible universe, but we reckon there are between 1080 and 1082 of them. As for the “Planck length” at which quantum effects start to dominate gravity, that’s estimated to be 10–35 metres. The transition between laminar and turbulent flow in fluids, meanwhile, comes in at Reynolds’ numbers of between 2500 and 4000.
These estimation skills, which are a familiar part of any physicist’s toolkit, can also come in handy for anyone working in the business world. In particular, the ability to estimate is useful when examining the business cases drawn up by start-up companies seeking to drum up financial support from investors and banks.
Most business cases completely overestimate a company’s predicted profits and make wild – and mostly nonsensical – statements
Such documents inevitably paint a rosy picture of a firm’s potential because, without money, nothing can be done. However, in my experience, most business cases completely overestimate a company’s predicted profits. They also make wild – and mostly nonsensical – statements about the transformational impact it will have on a particular industry.
Now I appreciate that business cases need to contain a bit of hyperbole if they are to attract investor funding; there’s no point being unnecessarily gloomy and down-beat. But given that up to 90% of start-up companies fail, it’s essential to have the ability and skills to evaluate a start-up company’s business case as realistically as possible.
Here’s the rub
Let me give you a specific example from tribology – the science of friction, lubrication and wear. Tribology might seem mundane, but it is a big deal, especially when you realize that 25% of the world’s energy is used simply to overcome friction and wear. (The Institute of Physics has a special interest group in tribology if you want to find out more about the field.)
One topic of huge interest, on which Google Scholar reckons almost 15,000 papers were published in 2025 alone, is that of nanoparticles as potential lubricant additives. Despite that large amount of research, I am not aware of any mainstream commercial lubricants that use any of these additives. So why is there such a large disconnect between academia and actual practice?
This is where our estimation skills come in. We know that lubricants are mostly hydrocarbon oils plus chemical additives such as antioxidants, friction modifiers, dispersants, detergents and anti-wear and anti-foaming agents. According to data from Kline and Company, about 40 million tonnes of lubricants are used annually around the world, roughly evenly split between industry and the automotive sector.
Automotive lubricants typically contain 15% additives, whilst industrial lubricants have about 1%. The “average” additive content, over all lubricants, is therefore about 8%, which equates to 3.2 million tonnes. With Polaris Market Research estimating that the lubricant-additives business being worth about $20 billion, we can see that the “average” additive price is roughly $6250 per tonne.
Particularly important to lubricants are anti-wear additives, which stop metal surfaces from breaking down when the oil that normally keeps them apart has disappeared. Lubricants usually have about 1% of such additives. Given the numbers above, we can estimate that the overall market for them should be about 400,000 tonnes.
That’s not far off the real market size, which business analysts Markets and Markets reckon to be about 300,000 tonnes. (The figure is slightly less than my estimate because some lubricants, such as transformer and circulating oils, don’t contain such additives.) With that market being worth almost $1 billion a year, the average price of anti-wear additives is about $3300 per tonne.
There’s also another key component of modern engine oils, namely friction modifiers – “slippery” substances that form films on moving surfaces to reduce friction and stop them from shearing. Some of the best friction modifiers, which are based on molybdenum, cost about $10,000 per tonne. Given that base oils typically cost between $1000 and $2500 per tonne, molybdenum-based friction modifiers are much pricer than anti-wear additives.
Graphene isn’t gold
Armed with this information, we can now see why graphene – the “poster child” of lubricant nanoparticles – has flopped so badly from a commercial point of view as a lubricant additive. This 2D carbon material costs a staggering $50,000–$200,000 per tonne, which is more than five times pricier than the most expensive additives in lubricant formulations.
The message is clear. For lubricant nanoparticles to become commercially competitive additives, their price per tonne needs to be come down by at least an order of magnitude. Now most Physics World readers are unlikely to be in the business of selling lubricants. But for anyone developing a new technology, the point is you cannot assume customers will come running.
Businesses need to be aware of what existing technologies are out there – and how much those rival technologies cost
Businesses need to be aware of what existing technologies are out there – and how much those rival technologies cost. If a new technology is too expensive for that application, different markets may need to be considered. Graphene, for example, has proved more useful in composites and materials reinforcement, coatings, energy storage and electronics, rather than lubricants.
Looking at new technologies even more broadly, the most successful by far are those that have fallen in price year-on-year for a decade or more. In computing, for example the cost of CPU time per dollar has typically dropped by a third every single year for the last 70 years, while computer memory has plummeted from $604trillion per terabyte in 1959 to just over $1000 per terabyte in 2023. As for electric cars, they are selling like hot cakes now that batteries have dropped from $10,000 per kWh in 1991 to barely $100 per kWh today.
My message is simple. When it comes to any technology, a sure-fire way to judge if it’ll succeed is to see if its price is likely to drop. No-one can know what the future will hold, but as physicists and engineers, we have a great ability to make estimations. By applying those skills when we sift through business cases, we’re more likely than most to identify the real gems from the rest.
Capital connections Janet Coyle from London and Partners addressing delegates at a meeting at the Institute of Physics to mark the first anniversary of the London Quantum Cluster. (Courtesy: Carmen Vilano)
“There are two types of people when it comes to quantum,” joked Howard Dawber, deputy mayor of London for business and growth at a meeting at the Institute of Physics last night to celebrate the first anniversary of the London Quantum Cluster.
“There are those who understand quantum mechanics. There are those who don’t. And there are those who are in superposition of understanding and not understanding until they are observed.”
It was a light-hearted remark that matched the mood of what was essentially an evening of boosterism for quantum technology in London ahead of London Tech Week next week.
As chair of London and Partners – the growth agency for London – Dawber told the gathering of more than 100 “quantum influencers” that the organization was “100% behind the London Quantum Cluster”.
Founded in 2025 by University College London, King’s College London and Imperial College London, with support from the Mayor of London and the UK government, the cluster seeks to establish the capital as a powerhouse of quantum tech.
Georgia Siora from Warwick Economics and Development presented data to show that London is already doing well in the sector, being home to more than 160 quantum companies, with seven of the top 10 UK quantum firms based in the city. Small- and medium-sized quantum firms in the capital, she added, contribute an estimated £153m annually to the economy.
Happy anniversary The London Quantum Cluster is now one year old. (Courtesy: Carmen Vilano)
“Quantum and deep tech are at the heart of the capital’s 10-year growth plan,” added Janet Coyle, managing director of London and Partners.
Geraint Rees, vice-provost for research, innovation and global engagement at UCL, said his aim was “to make London the best place on the planet for serious quantum companies”. He pointed to UCL spin-out Quantum Motion, which has just won $160m of venture-capital funding, as an example of the kind of firm making a name in the city.
The evening ended with a panel debate chaired by Jess Wade from Imperial College London, featuring Maria Maragkou from Nu Quantum as well as Richard Murray, founder of ORCA Computing, who drew a distinction between universities being all about expanding the frontiers of knowledge, whereas for start-ups “the aim is to win”.
Also on the panel was physicist Alejandro Montblanch – head of quantum communication and networking at banking group HSBC – who made it clear that what he wanted to know was: “How can your quantum company help HSBC make more money?”
A welcome note of caution came from London-based venture-capital investor Eloisa Angeles, who pointed out that while the UK has a good track record of government-funded research, the UK is weak at “follow through”, with the government not focused on procurement and not having the end customer of the research in sight.
From heatwaves to extreme rainfall, the impact of climate change is rapidly becoming a reality in our daily lives and a danger to our planet. But physicists are in a great position to help, with physics-based research bringing about practical, real-world solutions, whether it’s more efficient solar cells, better climate models, or novel materials for capturing carbon dioxide from the atmosphere.
There are huge economic and commercial benefits from such work too. A 2023 report from the Institute of Physics (IOP), entitled Physics Powering the Green Economy, estimates there are almost 1800 companies in the UK and Ireland taking green technologies to market with a combined turnover of £750bn.
Last year a follow-up IOP Impact report entitled Unleashing Physics to Power the UK Energy Sector identified the most promising physics technologies for transforming the UK’s energy system. These fall into three main areas: energy generation (nuclear power, photovoltaics), storage (batteries) and transmission (high-temperature superconductors).
The clean-energy revolution will not be easy, however. As the IOP report points out, the UK has a strong research base, good international collaborations, and a growing pipeline of spin-out and early-stage companies. But the country doesn’t invest enough in technology scale-up facilities, faces critical skill shortages, and isn’t great at recycling either.
To discuss how physicists are supporting the green economy – and what more they can do – a panel debate was recently held at the IOP in central London. Attended by Prince Edward, the Duke of Edinburgh, as well as about 100 business leaders, policy chiefs, senior physicists, and IOP and IOP Publishing staff, it was chaired by Tara Shears, the IOP’s vice-president for science and innovation.
The panel featured ex-BP boss John Browne, who now works in green energy, Emily Nurse from the UK’s Climate Change Committee, former Sizewell C energy-strategy director David Cole, solar-cell physicist Jenny Nelson from Imperial College, and Nellie Technologies founder Stephen Milburn. The following is an edited extract of the discussion.
Physicists for a greener future
Green game-changers Tara Shears (far left) chairing the panel debate at the Institute of Physics in London on how physics can support the green economy. It featured (from left to right) John Browne, Emily Nurse, David Cole, Jenny Nelson and Stephen Milburn. (Courtesy: Carmen Valino)
John Browne is chair of BeyondNetZero, a climate-growth equity venture firm. He was group chief executive of energy giant BP from 1995–2007, having joined the firm in 1966 after studying natural sciences.
Emily Nurse, who was originally an experimental particle physicist, is the director of net zero at the UK’s Climate Change Committee, which advises the UK government on reducing emissions and adapting to the impacts of climate change.
David Cole, an engineer by training, was at the time of the discussion director of energy strategy at the Sizewell C nuclear-power plant, which is being built in Suffolk in the UK. When complete, it is expected to meet up to 7% of the UK’s total electricity demand. He is now executive president, consulting, at energy firm Wood.
Stephen Milburn is a physicist who is founder and chief executive of the firm Nellie Technologies in South Wales. It removes carbon dioxide form the atmosphere using biomass, which can then be used as animal feed or construction material.
What role are physicists currently playing in our quest for a greener economy?
John Browne: I made a wonderful decision 60 years ago, when I was 18, which was to read physics. After graduating, I became an engineer, but over the last 30 years physics has come back in to my life as I’ve found myself doing something very important – trying to get to net zero. Physics, you see, touches absolutely everything.
All that I’ve ever done – whether it’s renewable energy or “old energy” [fossil fuels] in my old life – starts with physics. Whether you’re involved in chemistry, biology, electronics or engineering, it could not exist without a much deeper understanding of physics. We have to make sure everybody knows that – but I don’t think people currently do. They tend to think engineering is the only enabler for commercialization, but physics is there.
Emily Nurse: I started out as a particle physicist working at CERN on the Large Hadron Collider but for the last four years, I’ve been involved in climate policy and now work with the UK’s Climate Change Committee. We are the UK government’s official advisers on its climate targets – and assessing progress towards meeting those targets. As we celebrate global decarbonization to date, we need to remember it’s all underpinned by physics.
Take the rise of solar power for example, which has been the fastest growing source of global electricity generation for the last 20 years in a row. Solar installations in 2024 were double those in 2022. Along with wind, solar has led to a reduction in electricity from fossil fuels. We’re seeing the costs of solar plummeting and they just keep falling further.
In the UK, solar power has been growing more slowly, but it’s starting to pick up and is going to be a really important part of the electricity mix. We’ve also got a lot of wind here in the UK – it’s a very windy island after all. I would also like to give a shout out to heat pumps: as a physicist, how can you not love their efficiency?
David Cole: I am an engineer, not a physicist, but I’ve spent my career in lots of different sectors and been fascinated with the role that energy plays in creating a better society. What’s really interesting at Sizewell C is the ownership structure, which involves both state and private investment. It’s the first time private investment has been used for a new nuclear build in the UK.
I hope it leads to a virtuous circle, in which the more plants we build, the more we can reap from that investment
David Cole
Getting this hybrid financial structure over the line was not trivial – it took a lot of effort – but I think it will drive great performance. We’re also trying to use as much UK content in the plants as possible, whether that’s materials, skills or technology. I hope it leads to a virtuous circle, in which the more plants we build, the more we can reap from that investment. Sizewell C will, in other words, bring down energy costs, which is fundamental to economic growth.
Jenny Nelson: I have been active in research into solar photovoltaic (PV) materials and devices for over 30 years and we should celebrate how much has happened in the field during that time. In the last 10 years, we have seen capacity increase globally by more than a factor of 10, we’ve seen the efficiency of solar cells increase, and we’ve seen the cost come down almost by a factor of eight, all of which is remarkable.
Those innovations are firmly rooted in physics – whether it’s changes in device structure… or of the optical properties of materials
Jenny Nelson
The cheapest form of electricity globally, in other words, is now from solar PV, which was not the case 30 years ago. These developments have come partly from economies of scale and partly from technological innovations that have now fed through into production. Those innovations are firmly rooted in physics – whether it’s changes in device structure due to our understanding of semiconductor physics or new developments in the optical properties of materials.
The next generation of PV cells, which are likely to be silicon-based tandem devices, will also depend on scientific breakthroughs and innovations.
Stephen Milburn: I’m chief executive of Nellie Technologies, which is based in South Wales on the site of a former chemical-weapons storage facility. We’re using biomass waste for removing atmospheric carbon dioxide, and if you visit us, you’ll see all kinds of activity: in one corner there’s chemistry, in another engineering and in the next there’s biology and biochemistry. But physics is at the heart of the technology. Physicists are a bit arrogant when we say we think we can do everything, but the fact is we probably can.
But we should also celebrate the work that has gone on to create a market in which carbon-emission credits can be bought and sold. Trading carbon credits has been a bit of a dark activity over the last 10 years, with double counting and bad things happening purely by firms wishing to make a profit. However, the market does have the power to regulate itself – in fact the alignment we’re starting to see between the UK and the EU will help greatly.
Challenging times Technologies to store, generate or transmit energy are rooted in physics. (Courtesy: iStock/Galeanu Mihai)
What are the biggest growth opportunities for the green-economy sector?
John Browne: First, we can do much more with what we’ve already got – for example we could increase our offshore wind or rethink whether we should go back into onshore wind. Second, we can improve what we’re doing – for instance, by increasing the efficiency of solar panels to their theoretical maximum, which would make rooftop solar economically attractive. Third, there are new opportunities, such as metallic organic frameworks and nuclear fusion.
What we do here in the UK needs to move the needle globally, which means thinking about how to scale and finance it properly
John Browne
However, the UK needs to avoid doing things that others are doing much better. The race for the best battery in the world is, for example, probably going to be won elsewhere. What we do here in the UK needs to move the needle globally, which means thinking about how to scale and finance it properly. The UK shouldn’t end up as a secondary player.
Emily Nurse: The UK has made a lot of progress in our quest to reach net zero by 2050. Since 1990, for example, we’ve halved our carbon emissions, mainly by decarbonizing electricity – phasing out coal, reducing gas generation, while significantly increasing wind, solar and other renewables. Electricity generation now accounts for only around 7% of UK emissions, which are dominated by transport (cars and vans) and heating (oil and gas boilers).
Reducing emissions still further will predominantly come from moving to electric technologies, including electric vehicles and heat pumps, and by further decarbonizing the electricity supply. There will be a backbone of wind and solar, but to ensure a secure supply, we’ll need nuclear, carbon capture and storage, hydrogen and batteries. We’ll have to reduce emissions from agriculture and land use too.
A report from the Confederation of British Industry (CBI) last year estimated that the net-zero economy grew by 10% in 2024, which is three times faster than the rest of the UK. But we’ll need more innovations to continue to bring costs down – and we’ll also need to provide incentives to boost the take-up of electric technologies. If we do that, there’ll be an overall saving to the UK economy in about 15 years’ time, our analysis suggests. There are huge opportunities for green growth to come from this investment.
David Cole: I agree that for the UK to be competitive, the cost of energy has to come down – not just for domestic customers but businesses too. In fact, there are two main opportunities First, we have to adopt a “whole-systems” approach. If we’re building a power station, for example, can we use every bit to its maximum potential?
Let’s say I’m running a direct air-capture plant operating at 25–30 ºC – can I use the waste flow from my coolant system to encourage new industries? Can it support nearby hydrogen generation plants or companies making, say, synthetic aviation fuel? Those questions involve thinking about physics and engineering as well as materials science, which is also super important.
Whichever way you look at it, we’re talking about building a lot of hardware, which involves materials. How much energy per unit mass are they using? Can we recycle those materials? What can we do with the waste products? Ultimately, what is really important is energy security: where does your energy come from, who made it and what impact does it have on the environment?
Jenny Nelson: The net-zero economy is growing significantly faster than the rest of the economy and I think that will continue. But decarbonizing the power sector only addresses part of the problem and we’re going to see a big transition across the rest of industry, agriculture and elsewhere that will generate a wide range of opportunities and stimulate the economy too. I’m not just talking about rolling out more renewables, but about integration – bringing together the generation and storage of energy, ensuring that we are managing demands and have the right infrastructure.
As for my area of photovoltaics, we’ve seen great ideas and technologies come out of the UK that are very likely going to be developed outside the UK because the manufacturing capacity isn’t here. Nevertheless, those ideas and innovations can still benefit the country through licensing, partial manufacturing and new technology.
One thing to remember about solar power is it’s distributed. You can have solar generation without being connected to the grid. That not only opens some markets for certain applications where you want to generate electricity locally, but it also provides a route to energy security through back-up generation, towards which solar power will be an important part.
Stephen Milburn: Having a strong green-technology manufacturing base is a huge opportunity for the UK. My company is based in South Wales, where we have lots of highly skilled people who used to work in traditional industries but now don’t have many places to go. Yes, there’s a fantastic semiconductor industry here, but when it comes to deploying green technology we cannot outsource that responsibility to other parts of the world.
Green tech needs to be deployed in the UK’s industrial heartlands… if we don’t nurture jobs and skills here there’s a real risk they will be gone forever
Stephen Milburn
Green tech needs to be deployed in the UK’s industrial heartlands to take advantage of the skills we already have, but which we are at risk of losing. In fact, if we don’t nurture those jobs and skills here there’s a real risk they will be gone forever. Having a strong green-technology manufacturing base is a huge opportunity for the UK.
Deep thinkers Combining analytical minds with great problem-solving skills, physicists are well placed to tackle the challenges of climate change. (Courtesy: iStock/MTStock Studio)
What needs to happen so that these opportunities can be put into practice?
Stephen Milburn: Many science graduates leave university equipped with solid academic rigour and a great scientific understanding, but they often lack practical green-technology skills. This summer my company is therefore hoping to launch a climate apprenticeship programme, which will allow graduates to pick up those skills. We need to build green-tech skills in the real economy, in particular those that will deal with climate change.
Jenny Nelson: The UK must do more to support its own innovations. We need better regulations to avoid unnecessary bottlenecks. We need to invest in infrastructure like the grid. We should completely avoid subsidizing fossil fuels and instead divert any subsidies into alternative economies. Finally, we need to train and educate people, showing the public the potential of green technology so that they become part of the transition, for example by generating their own electricity.
David Cole: We need to integrate our policies on industry, energy, land use and AI so that we can invest in them all as growth areas. In particular, I’d like to see a long-term nuclear programme in which we build a fleet of new reactors all of the same design, which will drive down costs by letting us replicate a particular technology. It’s also vital that we get a high proportion of UK content and technology into these reactors, which will lead to a virtuous circle, with money coming back into the economy that we can re-invest in industrial and academic partnerships.
Emily Nurse: What’s vital is consistency in policies; we need certainty. In the UK, we are fortunate to have world-leading climate legislation in the form of the 2008 Climate Change Act, which does not just make it a legal requirement to reach net zero by 2050 but also gives us targets along the way. It means we know what we need to do in both the medium- and long-term, which gives certainty to investors, businesses, innovators and consumers.
What’s really important is communication – supporting communities through the transition and making sure they realize the benefits
Emily Nurse
So the first thing we need to do is keep the Climate Change Act. Then, of course, we’ve got to address barriers to delivery, including having the right incentives to electrify the economy. And what’s really important is communication – supporting communities through the transition and making sure they realize the benefits, not just in terms of reducing carbon production but of having cleaner, better and more efficient technologies too.
John Browne: First, we must never stop investing in people who can discover things and translate them into real commercial products. Second, we need to understand how to scale things, which means focusing on the winners and getting rid of things that are “nice to have” but aren’t going anywhere. That’s not easy because you have to push people to say, “You’ve done great work, but you’ll have to stop”.
What’s more, to scale new technology, people have to learn what it takes. When I’m in the US, I often speak to chief executives who can explain their technology to the financier who’s supporting it, whereas here in the UK that often doesn’t happen.
Third, we need to maintain confidence in what we’re doing. I often talk to people who think that it’ll be really expensive to get to net zero, but in fact estimates suggest that each household would only have to spend an average of about £150 a year to get there. So it’ll be less than the cost of a TV licence to get to net zero.
Of course the investment needed will be “lumpy” – it’s not as simple as just levying a fee – but the point about governments is that they can smooth things out. That is what they have done in the past and it’s what they should continue to do.
For more information about the IOP’s work on the green economy, click here. You can also keep up to date with the all latest research in the field through IOP Publishing’s series of open-access Environmental Research Journals at this link.
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