UK-based Paragraf has been making the news recently with its development of a Hall-effect sensor made from graphene that they have developed with feedback from partners including , the European Organization for Nuclear Research, which has become famous over the last decade for its Large Hadron Collider.
Hall-effect sensors measure the strength or the magnitude of a magnetic field. These devices are a nearly ubiquitous sensor technology used in everything from robot positional sensing to computer keyboards.
For Paragraf the development of the Hall-Effect sensor is the first of a wide range of graphene electronic devices.
Paragraf recently became a corporate member of The Graphene Council and we took that opportunity to speak to their executives about their strategies and aims in commercializing graphene-enabled devices.
We spoke to both Simon Thomas, Chief Executive Officer, Paragraf and Michael Francis, Marketing Manager, Paragraf. Here are our interviews.
Q: Based on your website, you seem to be highlighting your production process being compatible with current electronics production processes as well as a Hall-effect sensor you have developed. Are these two distinct business lines, i.e. a fully-realized Hall Effect sensor and a graphene that can be easily adapted into the production processes of other electronic device manufacturers?
Michael Francis: Not quite – it’s because our production process is compatible with current electronics production processes that we have been able to make a commercially viable Hall-effect sensor. The Hall sensor is the first device on a roadmap of sensors and solid-state devices that we aim to develop and bring to market. Our business model is to develop these devices, rather than to sell the graphene on wafer.
Simon Thomas: At the moment, were not selling graphene as a material because of lack of market demand. Additionally in the current product value chain, the commercial value from making devices is much higher than commoditizing layered graphene. That may change in the future. One of the reasons that the market for layered graphene is small is because no one’s really got to grips with making high quality devices from this type of material yet.
We are considering an IP licensing approach, this may be something we’ll pursue in the future, as a company it would be impossible for us to make all of the devices that have been speculated that could be made using graphene. As a result, we have a very open and collaborative model to work with other people and companies, or entities who have different ideas and different devices they may want to make. In these cases, it’s a partnership model that we’re looking for. We can provide graphene for them, but, of course, we want to protect our own IP.
It could be either a license or an alliance that we set up with companies to develop individual technologies. The grand vision for Paragraf is to enable every conceivable graphene electronic device to be manufactured and Paragraf alone is not going to be able to achieve this. But we can possibly take a pick of 10 or 15 that we can do here over the next 10 years while supporting other partners to achieve their technologies.
Q: Do you conceive of yourself as a sensor producer or as an electronics company? Are you just focused on sensors? Is that your expertise or is it more being able to introduce these production processes for electronics?
Simon Thomas: We are pioneering the pathway to getting graphene into a manufacturing-ready, scalable, mass-production infrastructure.
Our goal is to produce solid-state electronics – taking standard silicon or compound semiconductor lines and being able to integrate graphene technology into them, replacing or supplementing current active materials whether that’s silicon, gallium arsenide or gallium nitride, with graphene.
Our long-term goal is to enable electronics manufacturers to be able to produce the same kind of architecture of devices that exist today but replacing the active materials with graphene. But in order to to reach that point, you have got to go through a lot of proof points. Graphene has a bit of a reputation in that it’s not the easiest material to handle, its not the easiest material to use. Its sensitivities go beyond production into how you process it afterwards, which is slightly different to today’s established materials. This means that we’ve had to develop other know how and IP in the use of graphene and its application in devices and technologies.
To achieve this we’ve chosen sensing technologies as our first products as they present simpler production opportunities, before we then move further down the production line into solid-state devices and so forth. We’re trying to take a pragmatic approach by determining what are the simplest devices we can do first, where we incorporate less onerous processing steps such as metalization and passivation before we have to go into the full, complicated production line of solid-state transistors, for example.
As a result, sensors have become the starting point for us, their production incorporates a lot of the techniques we want to use in future devices. You only need a few of the processing steps at this point in order to make sensor technology. The company’s goal is to develop the increasingly complex processes required to get all the way through the solid-state device technology ranges. Optimistically that’s going to take 5 to 10 years.
Michael Francis: As a first product for Paragraf the Hall Effect sensor was a nice one to tackle. Making an atomic layer of material and then subsequently using it to build a device is a complex process with many challenges. The Hall Effect sensor, in terms of device architecture, is fairly simple, so kept the technology intricacy to a minimum allowing us to focus on ‘getting the graphene in’ as opposed to working on the fundamental device design.
The result is a device that simply demonstrates the power of graphene and the advantages the material brings when used as an electronic sensor. It’s a very good first product that lifts the lid on what using graphene can do and highlights the potential for all other electronics technologies that use Paragraf graphene.
The learnings developed in the process of bringing the GHS to market are therefore being transferred to the development of further products with increasingly more complex architectures. This will include other sensing and solid-state electronic devices.
Q: What is the commercial status of the Hall Effect sensor? You seem to have relationship with CERN. Are they using this sensor? Do you have other customers? If so, what applications are they using the Hall-effect sensor?
Michael Francis: At the moment we are supplying ‘engineering samples’ of the graphene Hall sensor (GHS) to first lead partners and we are working closely with a number of these partners (including CERN and Oxford Instruments who are both users and development partners) to gain valuable feedback on their use of the technology. We made our first sales to these types of lead partners in 2019 and we are aiming to launch our first ‘on the shelf’ GHS product at the end of this year. We have found and are working with partners on a large number of applications for the GHS. This includes in applications such as mapping and calibrating permanent and electromagnets (being used at accelerator facilities, in R&D labs, in quantum computing, in MRI, in electric motors etc.), characterizing the efficacy of magnetic shielding, in battery research, and precise angular positioning of components.. Since we have recently shown that the sensor can be radiation tolerant (partnership with NPL) we can look at Space/aerospace applications too.
Q: You’re doing this work with CERN and I guess one of the application areas would be in accelerator facilities. There’s not a lot of accelerator facilities in the world. How many devices can you sell? How big is the market for something like that?
Simon Thomas: Hall Effect sensors are pretty ubiquitous. They’re used in many ways and many applicatons. But they’re typically two cents, five cents a sensor. However, there are some very high-end applications for Hall Effect sensors that have improved performance characteristics, which, are being enabled by our sensor.
For example, if you have higher sensitivity and you’re able to operate in low temperatures, positional sensing for satellites becomes an opportunity. Also, there are medical devices, such as MRI scanners, where high accuracy magnetic sensing would improve the imaging capability. There are lots of applications, not just in applications that exist today, but that are going to be enabled by having this sensor because its performance properties are so far beyond what’s available currently.
A great example, is dilution fridges and cryostats for example for use in quantum computing. Currently it is not possible to sense the magnetic fields that the user is highly reliant on at low temperatures, and that’s because no sensor existed able to do this, until now, thanks to Paragraf’s GHS product.
We’re not going to be able to just run out billions of sensors a week, in the near future, and conquer the current markets or the five-dollar laptop sensor market, but that’s not what we’re targeting. Our goal is to enable new capabilities through the application of graphene which in turn will enable new and improved exciting technologies.
Q: What are the unique selling points of this Hall-effect sensor as opposed to similar sensors made with more traditional materials?
Michael Francis: USPs include:
- High resolution –In terms of resolution the GHS performs far beyond that of a Hall sensor and more like Fluxgate sensors and NMR probes
- Cryo temperature operation – the only Hall sensor to work and be useable at mK temperatures
- Lack of planar Hall effect – clean signal with high confidence that the signal being measured is only coming from field components, which are perpendicular to the plane of the GHS. Traditional Hall sensors pick up on stray/in-plane fields which limits resolution & accuracy
- Low power (pW with nA drive) – useable signal produced under low power conditions. Even the standard drive current is 1-2 orders of magnitude smaller than other Hall sensors. Heat dissipation is >6orders of magnitude less than any other Hall sensor – again making them ideal in cryogenic situations.
- Repeatable linearity – easy to calibrate
- Repeatable temperature coefficient – easy to calibrate.
- High temperatures should be possible – limited by packaging, not graphene. “High-T Hall” Innovate project with Compound Semiconductor Applications Catapult, TT Electronics Aerostanrew and Rolls Royce is ongoing and aiming for >175 C.
- Variable Voltages / Currents can be used – can match rails already in component.
- Robust – High voltages, ESD, thermal shock, radiation tolerance
- Large dynamic field measurement range (+/- 14T) – doesn’t saturate at high fields (where other Hall sensors, xMR and Fluxgates/NMR probes do)
Q: Graphene’s characteristics and properties make sensor applications a kind of low-hanging fruit in its overall applications in electronics. Is there any sense that sensors may constitute the end for graphene in electronics applications?
Simon Thomas: The properties of graphene are absolutely suited to sensing technologies. I think you can see this in not only what we’re proving already, but also in what other people have done in the lab. The big challenge is whether you can get graphene through all of the processing steps that are required in order to make the more complex technologies at a volume level.
Graphene is a material that requires some love and care to use it successfully in devices. We are already quite a long way down this road. In fact, we already have more and more complex devices being produced at our facility now. They are currently mainly proof of concept but scaling to the mass manufacturing breakpoint is what we’re rapidly driving towards. My current feeling is that there are still tweaks or modifications to processes for making solid-state devices out of graphene that will be required to get graphene to work effectively.
We have no indications now that that won’t happen. Now, I might be wrong, we’re not an equipment manufacturer and there may be unforeseen challenges still to overcome here. We know what the equipment needs to do for us, and we might find we get to a point where equipment manufacturers turn around and say, “Actually, this is going to be a real bottleneck or it’s going to be a brick wall.” We haven’t seen that yet, and we are working with a lot of different partners on this type of stuff, particularly the device processing line side.
There are a lot of equipment manufacturers now that are heavily focusing on graphene processing tools. However, we may reach a point that we have to wait for those tools to catch up. But I think that the demand and the performance characteristics of what we’re showing will be more than enough for those tool manufacturers to want to put those efforts in.
I currently don’t see, and our technology team hasn’t seen, a showstopper. We have seen challenges, but we were expecting there are going to be challenges. As a result, it may take longer than those 5-10 years for particular graphene-based electronics technologies to be realized, particularly the more complex ones, because these challenges require a support base around us to be able to achieve. However, I perceive—and I have spent quite a lot of time in this field now— that there are engineering challenges still to be resolved, but the scientific challenges are dropping away. I think once you reach that threshold where things become engineering challenges, they are usually surmountable.
Q: What were the greatest challenges in getting this graphene-based Hall-effect sensor to work? And how did you overcome these challenges?
Michael Francis: The biggest challenge is really the key thing which Paragraf have solved – synthesizing graphene direct on wafer in a way which is commercially scalable. The rest of the development work is really then optimization and tailoring towards applications.
Q: What has been your experience in working with other electronic device manufacturers in getting them to adopt graphene into the manufacturing of their devices, i.e. price, lack of knowledge about graphene, concerns about the supply chain, etc.?
Michael Francis: Currently, all sensor volumes are produced in house and we have the capacity to scale to significant volumes in house in line with shorter term market requirements. However, we are engaged with several well-known partners. There may be opportunities in the future to strategically align with other companies, in which case licensing could become an option, as could JV or other partner opportunities, as our technology portfolio grows.
The biggest challenge so far has been in convincing manufacturers that we really can produce graphene in a format which will be commercially scalable for electronic devices. However, the delivery and commercialization of the GHS technology has helped us to get past that barrier and strike up some meaningful conversations with strategically aligned partners.
Q: When do you think you will reach the point where other electronics companies will look at the work you have completed with CERN in the development of Hall Effect sensors and come to you to develop an electronic device they want to develop?
Simon Thomas: We have a lot of ongoing conversations with potential partners and collaborators, many of whom have approached us with their ideas. For example, one of the big challenges for the motor industry, particularly in aviation and cars, is transferring over to electric motors. Problems exist with electric motors in how you efficiently apply the drive you want to the motor to get the highest performance and lowest energy usage. In automotive, if you use a bit too much energy, then you can charge your car again as soon as you park it. However, with aircraft, if we can get to the all-electric engine stage, there’s nothing you can do in the air if you run out of electricity.
So, one of the challenges that’s been presented to us is if we can sense highly accurately the fields inside an electric motor that is driving an aircraft engine so that they can optimize when they apply a drive current to the engine to achieve optimal power application and maximise flight range.
Further, we have a project we’re working on at the moment with Rolls-Royce to apply our sensors in a very effective way to essentially energy manage new aero engines.
Other parties have approached us based on what they’ve seen us do with the sensor and asked if we can improve the efficiency of other solid-state devices, such as high-power emitters or detectors. Graphene is an ideal material, as you know it has a very high-power density capability so there are very good opportunities in this field to, for example, improve the capability of external networks.
Originally published here.