Paragraf, has demonstrated the ability of its graphene Hall Effect sensors to withstand high levels of radiation. Electronic Specifier talks to Co-founder Ivor Guiney.
The discovery, based on testing from the National Physical Laboratory (NPL), proves that ‘unpackaged’ Hall Effect sensors can be used in high-radiation environments such as space. The project was funded by Innovate UK, the UK’s innovation agency.
Electronic Specifier Hello and welcome to today's podcast hosted by electronic specifier insights. In today's session we'll be talking to either Guinea who is technical director at paragraph either has a wealth of experience in physics, engineering and semiconductor materials and has led product projects which have developed new combinations of functional materials with the aim of linking innovative science with real world applications. Today, either we'll be telling us a little bit more about paragraphs, graphene Hall Effect sensors, which have now been certified for high radiation applications in space and beyond. So without further ado, I will have to either
thanks, Joe. Good morning. Good to be here, turbo teammate. So we'll probably do is just go through some, I suppose initial introduction to the technology and then go through what we've actually been doing with our good collaborators of National Physical laboratory in London, who have done the radiation testing of the whole sensors for us. So just to go through, I guess, a little bit of an introduction to paragraph, we're really a new company, we were only launched in 2017. And we're spun out from the Department of material science at the University of Cambridge. So I'm one of the founders, obviously, my two co founders are Professor sir Calvin Humphreys, who was head of the group, and Simon Thomas, who is now the CEO of paragraph. So at the moment, we have over 40 employees, which is a lost first GM company, and we're still expanding, we hire someone nearly every week. And of those employees, about 43% of them at the moment are in r&d. So we're constantly developing constantly innovating the material that we have and the products that we have as well. And in our facility, which is based in north of Cambridge, we have custom r&d facilities and in house production for graphene, electronic devices as well. You can think of us at the moment as a small semiconductor device fab we have synthesised the graphene processes to patch devices. And of course, we're continuing. So what what are we trying to do? We're trying to deliver for the first time really the game changing commercial graphene electronic technologies that have been that have been hypothesising process for such a long time. And we're trying to do that at scale. So our goal is to deliver these next generation electronic technologies for the benefit of the global community. graphene has been around for quite a while and many, many, many fantastic electronic devices have been made from graphene in university laboratories and divorcees around the world. We are attempting to, to take some of those results, in essence, scale them up and commercialise them and our focus is on the development of two dimensional materials in general and graphene based electronic technologies of course, So, forth we actually do is we synthesise graphene on top of semiconductor wafer surfaces. So, think of this in very simple terms of suppose, as a layer of carbon on top of an existing semiconductor wafer on top of silicon wafer software wait for the compound semiconductor wafer and others. And then because
it is in essence just a layer of carbon on top of semiconductor wait for
each we can go through standard semiconductor processing and production facilities. So it enables the fabrication, processing and production of graphene, graphene electronic devices really. So, our graphene is directly compatible with standard semiconductor processing as I said it is silicon capacitor. And the devices have already demonstrated step change improvements over existing technologies. So, at the moment, our first product was a was a graphene Hall Effect sensor is a magnetic sensor. So you might ask why is graphene particularly safe? graphene gives an extremely high sensitivity to magnetic fields, it's really possible to detect a very, very small magnetic fields with graphene The reason for that is because of graphene is very very low inherent carrier concentration. graphene is also capable of detecting a wide limit wide range of magnetics. So many Hall Effect sensors in their in their base states without any electronics to amplify them or to improve them are limited to a few tests and magnetic field. We can go to much higher fields and last, but also we can detect extremely low magnetic fields, because of the high sensitivity of the material. The graphene is extremely robust. It has very high mechanical strength anyway. So it has it has a great Theatre of resistance, a term of an electrical shock. And because of the fact that it's only a matter of carbon, that it doesn't have a bandgap, that it's transparent to radiation, it's really, really a tolerance to high levels of radiation, which something I'll get to in a minute. It has really low noise. So the sensors that we have created have a resolution of 700 nano Tesla's and that's way beyond what's the shape of it, a regular whole sensor is usually in the 10s to hundreds of microtesla. So orders of magnitude improvement, the sensor consumes very low power, with a very low drive current. So our standard operating conditions consume Pico watts of power. It's impervious to stray fields, because there's no planar whole effect. I'll talk more about that in a minute. And there's a release of calibration, which is something that our customers really liked at the moment. The linearity of the sensor is very repeatable and very good, and it has a very repeatable temperature coefficient as well. And for those customers who are interested in measuring extremely accurately magnetic fields, or extremely low magnetic fields, because you might want to compensate the linearity of the temperature slightly. There's a simple polynomial fish for nonlinearities. And that, again, is much easier than than existing hot sensors at the moment. And as well as that there's a wide operating temperature range. So at the moment, the product that we have is SPECT from liquid helium temperatures of minus 271 degrees Celsius to 80 degrees Celsius, both the ultra temperature limit is not graphene dependent there. It's actually packaging dependent. And that's something we are we're working on in the next iteration of the product. And I don't see an inherent problem with us, but we just don't have to market. Yes. So in terms of the lack of a planar Hall Effect, well, this was discovered in a collaboration, which we put out a press release about a couple of months ago with CERN, and we're very, very proud of this. centre is obviously a world class lab, and they wouldn't be using our devices, they think that we're good. So graphene is just a single layer of carbon. So it's a two dimensional material obviously. So, with that, you really can only pick up signals, magnetic field signals, which are perpendicular to the to the to the graphene itself. So it does not pick up spurious signals from non orthogonal fields, that really improves the mapping accuracy. So to give an indication, as measured in CERN, the magnitude of our planar Hall Effect is at most 10 to the minus five Tesla in a one Tesla field. And that's about two orders of magnitude better than any other Bayer hole sensor.
Now, you can actually compensate for that. For the for 3d effects in sensor using compensation electronics, which is what is done in existing Hall sensors on the market. bullish what we're saying is that our sensor with no compensation electronics at all, is as good as existing Hall sensors with electronic composition with plane at Hall Effect compensation compensation. We had our sensor is smaller, it's cryogenic compatible, and it's able to measure a much wider dynamic range, as I said, so it's really really versatile, really rugged exhibits, exams, USPS that you just cannot get from other technologies. So are graphene hellsten? Sure, it's, it's available. It's available on our website, but to go through some of the effects of data when compared to with other magnetic fields, measurement devices, it really really does perform well. As I said, the minimum power dissipation is extremely low. With other types of magnetic sensitive equipment, such as other hold sensors, such as devices like fluxgate, and other more probes. They all consume milliwatts of power at their lowest and in some cases, it's quite a lot more than that, for as I said, we consume. The planar Hall Effect is orders of magnitude better than magnetic fields range is up to plus or minus one Tesla. At the moment, it's possible that we can detect more than that we just haven't done the test yet. And with existing old sensors with flux gates, where the more probes, you're looking at three, Tesla's and much lower. Also, we can use it in cryogenic temperatures, as I said, we can measure gradient, magnetic fields with us. And the size and weight is extremely small. So the sensor itself at the moment, as per our website, is about eight millimetres by eight millimetres by 2.8 millimetres high. That's something we can scale down, we can make it even smaller. It's something that we're working on at the moment. So as I said earlier, we're in collaboration with the National Physical laboratory in Teddington in London, which is one of the best, the best, the best measurement labs in the world, really. We have an innovative UK funded grant with them. And the idea of that grant is to measure the graphene Hall Effect sensor in extremes of conditions. And one of those conditions is to it's a test and very, very high levels of radiation. So the theory here that we had was because graphene is transparent, because it doesn't have a bandgap because it's so thin, it should actually be impervious to radiation, in essence, the radiation should fly right through it.
And it shouldn't have any effect on sensor performance at all. But something we obviously didn't know it was just theory.
So we set up this France, this collaboration with the NPL to do justice. And I have to say the NPS have been have been excellent here. I can't speak highly enough of them. They've they've given us excellent results, and they've done it very quickly, in spite of the fact that they were locked down for a few months. So following testing by the NPL, it's been proven that the unpackaged graphene Hall sensors can be used in high radiation environments, such as space, such as the potential for upgrading in areas of high radiation, for example, in nuclear decommissioning. So why is this important? Historically, the deployment of all sensors in high radiation environments has faced a lot of challenges. Really, it's been quite complex, it's been lengthy it's been it's isn't as a safer costly manufacturing process would be the best way of putting it because you can get sensors, Hall Effect sensors and other sensors to go into space applications to go into applications of high radiation force. In all cases, the material which might be silicone, it might be something else will need to be packaged in a very specific way a very expensive way it will need to be it will need to have radiation hard packaging associated with it. What we're saying is that without any radiation, hard packaging at all, just with our standard sensor, tests conducted by the NPL have shown the following exposure to high extremely high neutron dose rates. paragraphs, graphene is just not affected by the radiation. In essence, radiation, as I said, plays right through it. So this is the first time that's commercially available graphene base electronic device has proved impervious to these levels of neutron radiation to very high levels of radiation. So the ability to perform under high radiation conditions isn't paved the way for the deployment of a broader range of electronics and in harsh environments, and paragraphs scalable manufacturing process for larger graphene deposition means it's possible to produce other radiation resistant graphene based electronic devices without having to resort to complex and expensive radiation hurt packaging. And it's important to point out as well that these results are extremely promising, but they are just for neutron radiation. And it did work extremely well in the neutron radiation. We have also set up some alpha, beta and gamma radiation testing at the MPO, which is imminent, actually, as they've emerged from lockdown, as well as some high frequency testing of the devices. we fully expect this to open up new opportunities across critical applications such as current sensing, in fact, and other applications for graphene call centres as well. So we're absolutely delighted with how this is going, really. The theory that we had appears to be holding up holding up very well with Getting fantastic results, which are proving new capabilities for the sensors are very excited to see what the what the upcoming tests will prove.
Okay, thanks very much either. In terms of questions. Firstly, could you perhaps go into a little bit more detail about the testing process at the NPL on, you know, what exactly was you know a little bit more about the process and what exactly was undertaken?
Sure. So the NPL has absolutely fantastic fantastic facilities for for radiation experiments. in general. They, they have a particle accelerator there, and they have exposed the sensor to, as I said, neutron radiation coming from California to 52. source. So they put sensor into magnetic field test is irradiated with with neutron radiation in their, in their, in their facility in their particle accelerator. And then they re measures on force, they actually have phones is that the measurements before and after the radiation testing were assessed the identical sensors suffered no degradation and performance. So now, as I said, we haven't done the alpha, beta and gamma testing yet, but that is imminent. And we're at this stage extremely confident about that. Because if it is impervious to one type of radiation, it doesn't make sense that it would be impervious to the others. So we're looking forward to those results.
Okay, what's the timescales? Are you looking at with regards to the testing process?
weeks? So really, quite soon? It would have been done by no if if the MPL hadn't been unfortunately shut down due to the COVID situation. But they ramped up their facilities really quickly, again, we have supplied them with new sensors for these tests, and they should be done very, very soon. And Dude,
I see. I see. And in terms of the technology itself, how has it taken until now for a commercially available graphene based sensor to be to reach a stage where it's impervious to to neutral radiation,
I suppose it's important to remember that graphene is still quite young material, it was only isolated in the lab in 2004, Nobel Prize was awarded for 10 years ago. In some ways, it just is quite normal. For it to take this long for material tourists to emerge from basic research to commercialization. Both I don't want to take anything away from from what we've done here. The graphene production method that we have is extremely, extremely straightforward in order to create a full electronic devices, if really gives repeatable and reproducible materials with good uniformity across the wafer such that if you create electronic devices from us, you do get the same device from batch to batch from run to run. And also, the technology team in paragraph has done has done a fantastic job at working out how to process the material and how to package it in a commercial setting. Because, you know, in essence, this just hadn't been done before. So we have developed a large amount of IP in this book in terms of patents, obviously, but in terms of Tracy for de novo as well. And we have done this in extremely short period of time.
I see I see, as you mentioned that it's a relatively rapid is relatively new material. So do you think we're, we're merely just scratching the surface now in terms of its its application potential?
Absolutely. So graphene, it really does work well as we have proven as a whole sensor. But it works fantastically well in many other electronic devices as well. There have been many, many papers published, showing graphene working fantastically well in solid state devices in different types of sensors. So once you have the ability to produce the material at scale, in a cost effective way, and once you have, as importantly to once you have the ability to process the material to packages, and to make sure those those products, those practice devices are stable. And you have the ability to to produce normally identical devices from run to run from batch to batch. Well, that's that's been the missing links and missing keys to getting graphene from from research laboratories into the commercial world.
I see I see. And in terms of cost, how does how does this cost of you know, graphene will affect affect sensors compared to other types of magnetic field sensors.
So at the moment, we're engaging with partners on an application by application basis. So some people want to use Hole sensors for, as I said, very high magnetic fields. Some people want to use extremes of temperatures, we're hoping that people will now want to be interested for extremes of radiation, for example, we're very interested to discuss with people and their applications so we can figure out what it is that they need, figure out if there's development needed from our side, and, and discuss with them about other costs and so on thereafter, it's important to remember as well, that's part of our core technology, is that yes, we can develop graphene materials, we can develop graphene devices, but we can actually tailor these materials and devices at specific applications. So you know, if there's anyone out there thinking that the graphene Hall Effect sensor that we have, could mice use some improvements for a given application? We'd be very interested to hear about that, because we're quite bullish, quite confident about what we can do very confident about the capabilities of the material. And if something has to be done to modify it in a particular way, we were absolutely open to looking at that.
Great, great. And you mentioned earlier, that's some of the patents that the paragraph has for the technology. Similar to that, is there is there anybody else out there doing this? Similar thing with graphene all effects answers.
So there's been quite a lot of graphene Hall Effect sensor publications put out there from from different sources, and they work fantastically well. A couple of press releases out there as well, from from Institute's and from companies and these saying that graphene sensors have phenomenal potential before we're the only ones at the moment selling these on the market. So we're in a very good position.
I see. And in terms of applications for the paragraph, offering, do you see them? specifically? The uptake specifically being from the space sector and nuclear sector? Or do you see there being other applications? And if so, which What are they?
Yes, so we're getting a lot of traction at the moment for people who want to measure at very low temperatures, as I said, application for that would be measuring magnetic fields at very low temperatures in quantum computing applications. As well as the high sensitivity here, the extremely high sensitive fields, that shouldn't shouldn't be undersold in any way. You can use cold sensors as current sensors. And because of the fact that, in some cases, you will actually measure quite low magnetic fields, depending on what current through a particular part of the circuit is, you actually need a sensor with with extremely high sensitivity. So that will enable you to measure current a lot more accurately. And that is that is a massive advantage for manufacturers of big motors, to go into into planes, ships and others. If they can measure the power, sorry, the currents more accurately at different points of the motor different points of the circuit, they can actually switch elements of that circuit much more efficiently because they know exactly what the current level is. And that actually saved huge amounts of power. In the operation of motor we're talking kilowatts here. So foil, we say that the power dissipation of the sensor is very, very low as Pico watts. Depending on the application, there's actually a bigger power saving to be had here. And that is just using better sensors to monitor current levels better as an example. But to go back to your original question, yes, we see this being extremely applicable in space applications. Because the fact this just so rugged, nuclear decommissioning is another option. But you kind of see where I'm getting at here. The sensor has such USPS, in terms of sensitivity in terms of robustness to different stimuli, in terms of low noise, etc, etc. as I went through earlier, that the possibilities for this are enormous, absolutely enormous. They go far beyond what existing call centre technology is capable of.
Indeed, and just finally, IV. You mentioned that even without packaging the paragraph sensors are impervious to radiation. So, with that in mind, would they still would there be any applications where packaging would still be required?
So that we always use packaging With the sensors. To be clear, what we do is we use what I would call normal packages off the shelf packages. What we don't do is specifically tailor the packages for for high radiation or to withstand, you know, extremely high voltages or anything like that the material itself is capable of. So you'll always need to package it to some degree to fit into a circuit, whether it's through holes or surface mount bolts. At this moment in time, we have not seen the need to package it for specific applications because the material itself reacts so well defensively, like
okay, thank you very much either. This sounds like a very interesting and exciting technology. So it's great to find out more about that. For any of our listeners, there is a slide deck at the bottom of this podcast for free for an extra resource if anyone is offered any more information, but if you have any. If anyone has any further questions, then please get in contact with electronic specifier. And we can we can get those answers for you but for the time being thank you very much for your time either.
And thanks so much for being
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