Kiourti’s research has led to woven circuits that are as precise as
traditional PCBs.
Wearable form factors have been touted as a way to improve the stickiness of medical technologies, but even strapping on a fitness tracker or smart watch is an extra step that users may decide to skip. Thanks to new research, complying with therapy could soon be as easy as getting dressed in the morning.
Asimina Kiourti, an assistant professor in the department of electrical and computer engineering at the Ohio State University, is working on a technique of weaving electronics into textiles that might someday lead to smart clothing that can monitor vital signs and brain waves, and even track tumor growth. She answered some of Qmed’s questions about her research and will detail it further in a free conference session at the Advanced Design & Manufacturing Cleveland Conference at 11:15 a.m. on March 29, 2017.
Qmed: Can you explain the research you’re doing on smart clothing at the Ohio State University?
Kiourti: The idea is to have sensors that are embroidered somehow in the clothing and [can track] all types of physiological parameters—it can be heart rate, it can be sweat levels, motion of the human body. Right now, there are sensors like that, but they’re quite bulky, and they’re more accessories, like smart watches and smart bracelets. But all of these things right now are very bulky and obtrusive.
The idea is to integrate smart devices directly into the clothing, so have smart fibers, connected fibers woven into the clothes that achieve those functionalities. We’re able to embroider connected fibers into any type of fabric—it can be something very thin, like organza, or it can be something very thick and robust, like Kevlar.
Anything that’s right now built on rigid copper, we can just use connected thread and print it on the fabric, so it’s a flexible equivalent. It performs just like copper, but it can also be washed, it can be flexed, and it’s very robust. It can withstand very high and very low temperatures, and we have also done mechanical testing to show that that you can bend it multiple times and nothing happens to the performance.
Qmed: What were the biggest challenges you’ve had to overcome in your research?
Kiourti: So far, the biggest challenge we had was improving the accuracy of printing. When you have a printed circuit board (PCB), your accuracy can be .1 mm or even better than that. But when we first started embroidering the antennas and these circuits, the accuracy was like maybe 1 mm. If we had some designs that were maybe challenging or very fine, we couldn’t do that.
But in the last year or so, we were able to get some thread that’s very very thin, about .1 mm in diameter. Using those threads, we’re now able to print basically any type of PCB on textiles, so that really enabled us to pursue any applications, so now we can really replace copper with textiles.
The next challenge is to get rid of rigid components. Yes, you do print your circuit on textiles, but when it’s time to feed your antenna, to power it up, they need a cable. That cable needs a connect that you need to solder, so how do you get rid of that solder and the cable? That’s a big challenge to overcome.
Beyond developing the actual circuit, there are other questions coming up. For example, how do you power the devices. As of now, these are powered through batteries. But batteries, they’re big in size, they need to be replaced, they need to be recharged, so we’re exploring a fabric-based way to power these electronics without any rigid components or wires.
Qmed: How do you actually sew the circuits onto the material?
Kiourti: We have an automated embroidering machine. Theres’s nothing special about it. It’s just a regular embroidering machine that anyone could buy to do embroidering. It just has a port where you can import your files.
You start with computer software, and you design your antenna or circuit. The next step is to digitize your design, so that means that you determine the path that the embroidery machine is going to follow. You determine the path, where the needle starts and ends. We take that digitized file…import it, and then by the push of a button, you get your design.
Qmed: It seems like we’ve been hearing about incorporating electronics into clothing for a while now, so why aren’t we all wearing smart clothes yet?
Kiourti: At this stage, at least, wearable electronics don’t look fashionable. It’s not something someone would put on on a daily basis. The best place to start with is probably sports. That’s actually where we already see smart leggings coming out, smart socks to track the way you run or the way you move. As of now, people are targeting sports applications.
I also think we have [an opportunity] to target medical applications, for people who would really need wearable electronics to monitor their health status.
Moving forward, the goal is to eventually integrate these wearable electronics in our daily life. And for that, developers of these technologies would need to collaborate with fashion and people from design to be able to integrate these technologies in a really unobtrusive manner, so, you would put on a shirt or you have a purse that can charge your cell phone and you can’t even tell whether it has electronics embedded or not.
We’re not there yet because take the circuit itself. We can make it out of textiles, but the rigid components like, say, a temperature sensor or a cable, still require some soldering.
So, the technology is not there for people to use in their daily lives, but people like athletes or people who need medical sensors can totally make use of the technology while we’re trying to take it to the next step.
Qmed: What meaningful applications of smart clothing can we expect to start seeing in medicine?
Kiourti: Neurosensing is one area we’re exploring. For patients with Parkinson’s or some type of tremor, as of now, these people have to go to the surgery room, basically they open up the head and put electrodes deep inside to track what’s going on. One project we have is about having a hat or a cap, so a wearable device to place on the head. Then we have a tiny, small implant inside the head. The smart hat can interrogate your implant, and the implant can reply back with the signals, which means that you do not need to place any battery inside the head.
Another big area is tracking how the body moves. As of now, think of people who have sports injuries. The way they recover after that is with some motion capturing tools, so it’s like a huge room with cameras all around. The patient goes there and does some exercises, and the doctors basically see how they move. But it would be great if you could take the technology with you while you’re doing daily activities. Like at home or out, you have smart clothes that you wear and then with your cell phone you can basically track the motion and send the data to medical people as well.
Imaging is another product we’re working on. What we want to do is have, let’s say, a t-shirt that can image a cross section of the human body. Let’s say there’s a tumor that’s growing. You can monitor the growth just by wearing something that images a cross section. That would be a portable alternative to x-rays or MRI scans. Of course, you potentially cannot reach the accuracy levels of MRI with wearables, but you can still have a good picture of what’s going on and know when you should have an x-ray or an MRI. So, we’re developing a smart t-shirt to do that, and applications we’re targeting are either water accumulation in the lungs or monitoring tumor growth.
Qmed: Will smart clothing require us to change the way we do laundry?
Kiourti: It would be very hard to change the way we do laundry, so we would like to make this new smart clothing behave and feel just like regular clothes. Ideally, you wouldn’t have to remove any components, so you would just wear it, it monitors your vitals, you can see results on your cell phone, and then you can take the clothing and wash it, even dry it.
Eventually, even the battery could be something that’s printed on the fabric. It would be something that could be washed too, and you dry it and it still works like a battery.
Qmed: When can we expect to see smart clothing on the market?
Kiourti: As of now, all the products available in the market are for sports applications, so they’re tracking heart rate, the number of steps, the way you move. Some people use them for medical applications, but they’re not really approved for medical purposes.
The challenges of these devices right now are first of all, they’re not really unobtrusive, so you can see a bulky circuit sticking out, which is basically the battery. When it comes time to wash, you have to remove the circuit and then place it back.
Another drawback is that they’re quite expensive, so a smart t-shirt could cost around $400 right now. I would say in the next five years or so, we’ll see the prices of these products going down. And it’ll probably be a decade before we can actually have a device that’s used for medical purposes.
From:QMED
