>> I'd like to talk to you today about some of the technologies we've been researching with the idea of turning simple things like labels into sensors of everyday life.

>> So where would these sensors be? Well, they'll be on a range of objects all around us that we're used to seeing.

>> Things like parcels, where the labels on the parcels could do much more interesting things than just identifying. They could also tell you if the parcel has been mistreated in transit, if it's been dropped or shocked, if it has been exposed to dampness or the wrong temperature. This could all be picked up automatically by the label on the parcel. They might be on food packaging.

>> So rather than simply telling you the date by which you should throw the food away, the label could actually sense vapours coming off the food and it could now enable you to say, to find out that the food is about to go off it's reaching its prime ripeness, for instance, and therefore you should eat it now, and reduce the enormous amount of food wastage in modern society. 

>> They might go into medical dressings, plasters, bandages on the arm. They could tell you, not only that your wind is healing or that the dressing might need changing, they could tell you that you might be getting an infection and therefore should take a medication.
 
>> They might go directly on the skin as a type of transfer tattoo, and in this case, they could be part of a very comfortable low profile human-computer interface. So something you put on and then forget all about and it will carry on quietly functioning enabling you to interact with a system.

>> If you require long term care then you could have these sensing labels and devices on everyday objects in your home and they could therefore sense that you're living a routine and healthy life pattern and if you deviate from that pattern it could alert a carer that you might need extra visits to enable you to basically live at home safely.

>> Or if you're recovering from an operation or have a long-term condition or a disability and you require assistive technologies, in that case you could have the sensors built into your clothing, for instance, and then that could help you optimise your rehabilitation programme or your fitness regime.

>> So as an example of where this might be used, if we're thinking about the future of healthcare, which we know is a large issue to resource effectively. So what we were talking about is moving away from the current idea where you are effectively either 100% well or you are a patient and therefore ill.

>> So this is trying to bring in the idea that there is a whole spectrum of conditions in between those two, where on one end of it you basically are a healthy individual but you might not be living a very healthy lifestyle and therefore by using information about the life you lead, how active you are, what sort of foods you eat you could get back useful information to engage you, to motivate you and help you become a more healthy and active individual.

>> If you have a long term condition, in that case, where you need to self-medicate these sensors could help you do this very effectively, telling you when the medication is required and reduce the impact on your everyday life.

>> If you require long-term care you could have the sensors not only on yourself or your clothing, you could have them on the objects you use and therefore again we could work out if the assistive technologies given to help people stay independent are being used effectively, if they're the right technologies or if they need changing for something more useful.

>> And then at the other end we have the more traditional idea of a patient, somebody requiring acute or intensive care, who would be basically admitted into a hospital. Now, where would these technologies be, what are they and the whole point of the talk here.

>> We're talking about technologies which are not visible,  they should be very low key, they should be long-term so you put them on and forget all about them. Now that is difficult to achieve with modern electronics which can meet part of this demand but at the moment any electronic system will be based usually on a microprocessor as the sort of intelligent engine that will be interfaced with sensing modules and also interfaced with a wireless module, because of course, these things must be wireless to enable people to move freely.

>> Then, in order to support the microprocessor, we also have to have a battery and of course that brings problems to do with how long the lot the battery will last for, when it needs to be recharged, and also to accommodate the bulk of the battery in something that we want to be put on forget all about.
 
>> So, the work we're doing here at Kent is to get rid of that microprocessor, get rid of the complexity and to get rid of the battery that needs to support the microprocessor. Ok, so then we can start to move towards something which is like a vanishingly thin label, and then just get on with things.

>> So we want to move away from from this sort of manufactured electronics something which is done digitally by additive manufacture. And the idea being here that you don't have to be an engineer, you don't have to be a manufacturing expert, you simply need to know what the tag needs to sense. And in that case you could choose from a palette of different functions, the different things the tags need to sense, and you would take that to a printing utility and they would put those functions into the system.

>> And then by additive manufacturing or the addition layer by layer of smart materials they would form the specific personalised tag for you, getting around all the problems of shelf-life and transport needed when you have central manufacturing as we often do in modern society.

>> So the basic underlying technology that allows this to work, as I say it is going to be manufactured by additive manufacture, and here is some work we did at Kent with collaborators where we took existing temporary tattoo papers, and you can print a conducting pattern onto there and then by correctly treating the ink you can then make a tattoo.

>> It goes on the skin, you put it on and then you've got the basis of a human-computer interface which you just wear until you want to take it off. And as an example of how these tattoos work here on the slide you can see on the left hand side is a conventional existing hospital type of system.

>> So here you would have a spongy type electrode, it would have wet gel applied to it, it goes on your skin, and then we would pick up a heartwave form or and ECG and on the other side of the slide, on the right, you have a tattoo electrode and this is a dry connection.

>> It goes on the skin can stay there for at least a week, will survive the rigours of exercise, showering and so on.

>> And if we look at the waveforms associated with each electrode the blue is the hospital standard, the red comes from a tattoo you can see that the two, although they're not exactly the same, we can get a useful waveform from the tattoo electrode. And you can wear that for very long periods.

>> So how do we make these things wireless? Well with no battery of course there's a challenge there and the technologies that we're using are based on something known as RFID or radio frequency identification. And so in this particular case we use a system that works like a radar, it fires energy in, this energy is received by the tag and forms currents which energise the tag and the tag flashes back information on its reflected signal. And that information, basically, is used to identify the tag and any other information that it holds.

>> Now, of course, we want to do something a bit more interesting than simply identifying what the tag is, we want it to sense and to respond to stimuli in the environment. And therefore we do that by manipulating the currents that sit on the antenna on the tag, and you can see here the red colour shows you where the currents are very intense near the terminals that connect to the antenna's transponder chip.

>> So if we can manipulate those currents and we can do that in a controlled way in response to stimuli in the environment - we can turn the tag into a sensor. No need for any battery, microprocessor or other complexity, and the whole thing can be printed.

>> So here's an example of something that we've made. This again it's the idea of the tattoo, but in this case it's on the hard palate or the roof of the mouth and this is essentially responding to the position of the tongue in the mouth.

>> As the tongue moves, as it gets closer to the tag, it disrupts the currents and that can be picked up by the reader which is external to the body.

>> So the scenario we're looking at here is wheelchair control for people who have a severe disability that means they have no use of any of their limbs. And so here we found by using test volunteers that if we gave them targets to hit just by moving their tongue their accuracy actually became very, very high after just a few attempts, indicating that this idea is very very intuitive and is very promising as a way of realising tongue controlled joysticks - which could either drive wheelchairs or of course computer mice and that will allow you a human-computer interface.

>> Now it's a totally different example here's a tag which could go on frozen products in the chill chain.

>> So, these are products which are delivered by refrigerated lorry from processing plants to the store delivery, and, of course these products if they're frozen at point of departure they must stay frozen certainly until they're received by the store. And there is a danger, of course, associated with food defrosting and then refreezing.

>> So, these particular tags, they can exist in one of four states. They change state according to a metal plate which moves behind the tag and this this metal plate is manipulated by the expansion and contraction properties of water as it freezes and then defrosts.

>> So, depending on whether you're in state 1, 2, 3 or 4, this will signify if the tag is yet to be frozen, if it has been frozen, if it has defrosted and then finally if it is has then refrozen.

>> And if you're in state 4, the final state, you can only go through these states in order, so if you're in state 4 then you're signifying that the package has at some point defrosted and has since refrozen, and therefore of course it must be discarded. And all of this can be done throughout the point of transit, and we don't need any battery, the tag doesn't even have to be activated as these different states are gone through. So we can pick it up simply by reading it as the food is received into the supermarket.

>> Then as a final example I'm going to talk about, again this is a food packaging related scenario, but here we're talking about fresh produce and this is going to be something like soft fruits, which has of course quite a defined shelf-life. And so what we're going to use here to make the tag sense is the expansion or swelling properties of elastomer polymers - this is silicone - and as silicone is exposed to certain vapours it will start to swell and you can see the swell effect on the slide behind me as the silicone is exposed to a vapour over time it significantly expands.

>> And we can integrate this elastomer into the tag so that it will disrupt the feed mechanism and it will start to change how those currents flow across the tag as a result.
 
>> So here we can see on one graph we plot the effect of the vapour on the swell of the elastomer, so the elastomer is swelling getting larger and larger as it's exposed to three different vapours and notice that it's response is different for each one.

>> So in that case we can discriminate or select even between the type of vapours that the elastomer is receiving.

>> On the right hand side of the slide we can see the tag response to this, and so essentially, according to how much power we need at the other end of the link, we can work out if the tag has been exposed to a vapour and, of course, if that vapour is associated with the degradation of food or the ripening of food we can signify if the food needs to be eaten now or if it needs to be discarded.

>> So the message to take away, I hope you appreciate, we can make these sensing tags or we have the enabling ideas to make these tags without the need of any batteries, we can make them very cheap, we can print them at the point of need and there is a whole world out there of expansion possibilities to make these things basically sense in many, many different aspects of life.

>> We need to be able to make them biodegradable. Of course, if these tags are going to be widely used in packaging and widely used in the environment we can't add to the recycling end-of-life problems of electronics.

>> We want them to dissolve or to be deliberately degraded and allowing certain metals to be reclaimed at the end of life. And then of course very, very importantly if these tags are forming an intimate part of our everyday life we must also think about privacy and security making sure that our data stays private to be used in a way that we find acceptable.

>> So, thank you very much.