Medtech Engineering Secrets Found in an Ancient Art Form
Origami-inspired technologies have led to breakthroughs across many industries, including battery technology, spacecraft design, and yes – even medtech.
Over the years, MD+DI has reported on many origami-inspired technologies. In fact, in 2015, batteries inspired by origami came out on top in a series of surveys asking MD+DI readers to identify the new technologies most likely to have a profound effect on medtech in coming years.
Earlier that year, researchers at Arizona State University (ASU) used a variation of origami, called kirigami, as a design template for batteries that can be stretched to more than 150 percent of their original size and still maintain full functionality (pictured above). A paper describing how the ASU researchers developed kirigami-based litium-ion batteries was published June 11, 2015 in Nature’s Scientific Reports journal. The kirigami-based prototype battery was sewn into an elastic wristband that was attached to a smart watch. The battery fully powered the watch and its functions – including playing video – as the band was being stretched.
“Most wearables are going to require power, and for some it will be as much power as possible crammed into shapes that are awkward or needs to flex as the user moves,” Bill Evans, now vice president at Neptune Medical, told MD+DI in 2015. “I think a battery like the kirigami inspired design from the ASU team has a lot of potential in this emerging wearables market because of its ability to flex while in use, yet still offer the higher performance and well understood characteristics that lithium chemistry offers.”
The ASU researchers started out two years ago with the Miura fold of origami, Hanqing Jiang, a professor of mechanical and aerospace engineering at ASU, explained. The method, named after its inventor, Japanese astrophysicist Koryo Miura, involves folding a flat surface into a smaller area.
“Origami and kirigami belong to the fine arts. They have only been used by engineers very recently,” Jiang said.
Miura seemed to have potential when it came to providing some elasticity to otherwise rigid lithium-ion batteries. But Jiang and his colleagues, doctoral students students Zeming Song and Xu Wang, soon ran into a snag: Miura is stretchable, but the height changed significantly after repeated stretching. The solution Jiang, Song, and Wang landed on was a form of origami called kirigami that involves both folding and cutting. Kirigami enabled cutting and twisting to create interlocking structures of lithium ion batteries that were stretchable.
Origami also proved useful for Seokheun Choi, assistant professor of electrical and computer engineering at Binghamton University (Binghamton, NY). Choi came up with origami-inspired paper biobatteries (pictured below) that could potentially power sensors and other lower-power medical devices in developing countries.
The batteries include a air-breathing cathode created by spraying nickel onto a side of ordinary office paper. The anode is a screen printed with carbon paints. A drop of any type of bacteria-containing liquid can produce electricity on the paper biobattery. There was a significant design challenge, however. Choi needed to string a few of these paper batteries in a row in order to produce enough microwatts to be useful. A biosensor has space constraints. Choi, who earned a doctorate from Arizona State University, was aware of the ASU researchers’ work and the work of other engineers who had used origami. It provided an elegant solution for Choi.
“You could reduce the size by folding techniques. … I could connect 28 batteries to increase power density using origami technologies. I think this technique is a great potential tool for any biobatteryor any battery using paper-based substrates. It has a huge amount of potential,” Choi said.
Origami in the OR
In 2016, Researchers at Brigham Young University (BYU; Provo, UT) who had already been working with NASA to use origami principles in spacecraft design, began using related origami techniques to fashion surgical tools small enough to be inserted into holes in the skin that can heal without sutures. BYU licensed the technology to robotic surgery pioneer Intuitive Surgical. This video (transcript available below) details some of the origami-inspired technology BYU licensed to Intuitive.
The surgical device industry had reached a point in which it was becoming impossible to make surgical tools smaller using traditional instrumentation. But the BYU engineers were able to eliminate pin joints from some surgical instruments, using an origami-inspired design instead. For example, they created robotically-controlled forceps designed to fit inside a 3-mm hole.
“These small instruments will allow for a whole new range of surgeries to be performed, hopefully, one day manipulating things as small as nerves,” Spencer Magleby, a mechanical engineering professor at BYU, said at the time. “The origami-inspired ideas really help us to see how to make things smaller and smaller and to make them simpler and simpler.”
The researchers were also working on a device known as D-Core, which is initially in a 2-D configuration but expands to become two rounded surfaces that can roll to simulate the interaction of spinal discs. The device can be made from a single material. The researchers at the time had created versions from Tyvek, polycarbonate, polypropylene, and metallic glass. The D-Core research was published in Mechanism and Machine Theory in 2015.
Spencer Magleby, mechanical engineering professor, BYU: One of the reasons the medical industry is interested in origami is to create devices that are smaller, and they wanted a new concept – not just a smaller device, but a new way to think about the devices.
Robert Lang, origami artist, Robert J. Lang Origami: Origami is often useful in medicine for much the same reason that it’s useful in space. If you have something that is flat and sheet like but you want to get it into the body, you want it to go in through as small a hole as possible.
Spencer Magleby: Doctors are always looking for some kind of way to be less invasive or to be more precise or perhaps to do surgeries that require more precision, maybe working with nerves or something that is very small. BYU has recently entered into an agreement with Intuitive Surgical to license patents on devices that have been developed in our lab. Intuitive Surgical is a company that makes the da Vinci robot that does surgeries robotically. Here we can see one of their current devices that’s used to grasp things or to hold a needle to do suturing. the initial inspiration for the grasping device we worked on was an origami pattern that people commonly call chompers. Here is a large scale prototype that was based on some origami ideas of reducing the part count.
Unidentified speaker: So, you can see that here we we just have this 3D-printed plastic, and here we’ve actually moved to 3D-printed and stainless steel, and we were able to make the parts at this 4 millimeter scale.
Spencer Magleby: 3D-printing allows us to experiment the shape or prototype very quickly. I can have an idea from the computer to the 3D printer and into our lab for a look in less than a day. We have about a third or a fourth of the number of parts of a current device, so many fewer parts and the parts we have, the complexity of the parts, is lower. Our big idea is that we can make things smaller and smaller by using inspiration of things like origami that are very simple. So, instead of trying to make that complexity smaller and smaller, we’re going for simplicity early. These new devices that we’ve created to enable robotic surgery at smaller scales to be less invasive, we really feel like we’re going to make a big difference.