ORIGAMI ROBOTS: SELF-ASSEMBLING TOOLS FOR HEALTHCARE AND MORE

Transcription

1 ORIGAMI ROBOTS: SELF-ASSEMBLING TOOLS FOR HEALTHCARE AND MORE Lauren Judson University of Central Arkansas 201 Donaghey Avenue Conway, AR (678) Michael E. Ellis University of Central Arkansas 201 Donaghey Avenue Conway, AR (501) ABSTRACT Origami robots are self-assembling robots that can be deployed in a number of environments. This paper introduces the concept of origami robots and how they have evolved to their current state, discusses three main design approaches used in their creation, and their current use in healthcare applications. We also discuss possible future applications for their use and how they have the potential to impact areas beyond healthcare. INTRODUCTION Origami is most commonly associated with the Japanese art form of paper folding, but researchers across the globe are now starting to link this term with self-assembling robots. Researchers at the Massachusetts Institute of Technology (MIT) and Harvard University have dedicated years of research to the development of these self-folding robots with the intention of having them perform tasks in ways that can seem inconceivable. With the help of a magnet or motor, a flat sheet of paper can turn into a functioning robot that can be programmed to perform specific tasks without human intervention. The implications of this technology can have major benefits in many different sectors of business, but can be especially beneficial in industrial, healthcare, space, emergency relief, and retail sectors. According to an interview broadcast on Wall Street Journal Radio, researcher Lee Hotz talks to host Gordon Deal on the folding principles discovered and how they can be applied to any material that has the ability to be creased and folded (Hotz, 2014). Although the research explored thus far has been limited to smaller structures, with the assistance of continued research and technology, one day we can hope to see this in much larger and complex structures. Benefits from this technology can improve cost, efficiency, manufactured time, and even safety of those creating them. This paper will first explore the development and evolution of different self-folding robot designs, and focus on three designs developed by researchers at MIT and Harvard. Then the current uses for this technology will be discussed, specifically the use of origami robots to repair stomach wounds. Finally, the paper will show how this innovative technology can be used by

2 providing different examples of how these robots can be implemented within the business community. This paper aims to provide the reader with the knowledge of how origami robots and self-actuating technology can be of use to any discipline, in addition to creating a conversation of how else this technology can be applied. ORIGAMI ROBOT DEVELOPMENT Many different entities have created their own version of the origami robot. Although there are different methods, the concepts are similar in that the body of the robot starts out as a flat piece of material, but transforms into a three-dimensional structure. These structures are typically comprised of multiple layers of heat responsive materials that have a pattern etched into them. The pattern is similar to those you see in an origami instructional book, with a series of creases in specific areas. These patterns can be designed with the help of software and etched onto the layers with a laser etcher, or even by hand. When an energy source is applied to the systems, the heat created reacts with the layers, which in turn interact with the etched pattern. This reaction forces the layers to fold in the desired position. Of the many different ways to create an origami robot, we discuss the three techniques we believe could be the most impactful on future developments in the field of self-assembling robots. A. Self-pop-up Cylindrical Structure by Global Heating By Miyashita, Onal, and Rus The first of the three studies, Self-pop-up Cylindrical Structure by Global Heating by Miyashita, Onal, and Rus, was published in 2013 by a group of MIT researchers. The goal of this study was to produce a pop-up structure that can become the exoskeleton for an actuation device. The combination of these two properties creates this version of the origami robot. The key to creating this exoskeleton is in the strategic layering of materials, which transform an etched sheet of paper into a self-standing structure. For this origami structure, the layers were comprised of a supporting (bottom) layer and a structural (top) layer (Miyashita, Onal, and Rus, 2013). The group then used a laser-cutting machine to etch the desired pattern onto the structural layer. On one half of the layer is the pattern that would be considered the front, and on the other half would be the corresponding back. Based on the structure they are trying to achieve, there are some parts of the top layer that must be removed so the structure can hinge properly when selffolding. After this layer is peeled away, a layer of heat-sensitive contracting material called polyvinyl chloride (PVC) is inserted on top (Miyashita, Onal, and Rus, 2013). After this step takes place, the layers are folded in half so the front pattern is in sync with the back pattern. Finally, the supporting layer is completely removed just leaving the structural and PVC layer. For a visualization of this process, refer to Figure 1 in the appendix. Since the PVC material responds to heat, the patterns had gaps of specific widths etched in the front and back of the structural layers so the PVC could fill them in when the heat source is applied. To have the gap widths fill with the PVC layer at the same time, the source needs to be heated uniformly, which is achieved through global heating (Miyashita, Onal, and Rus, 2013). The structure is hung in an oven where heat is blown from the sides starting from room temperature (25 C/77 F) to the desired end temperature (65 C/149 F) (Miyashita et al., 2013). This process takes around five minutes for the shape to transform into the cylinder. For a time- lapse and temperatures, refer to Figure 2 in the appendix. After the completion of the global heating on the

3 origami structure, an actuation unit, consisting of two vibration motors for locomotion and a circuit to control the movement, is placed in the hollow area of the cylinder (Miyashita et al., 2013). B. A method for building self-folding machines by Fulton, Tolley, Demaine, Rus, and Wood A team of Harvard University researchers published the next study in 2014 called A method for building self-folding machines. This research took similar principles, but had some modifications in the process and materials used. In the previous study, the actuator was added to the origami exoskeleton after the global heating process took place. The Harvard researchers created their pop-up robot with the actuator physically attached during the folding phases. To accommodate the two attached motors, the etchings account for areas that accommodate this add on. These include locking tab, crank arm pin, and alignment tabs. The layers that make up the material used are comprised of two outer layers of prestretched polystyrene (PSPS), two layers of paper, and a layer of polyimide (PCB) bearing a copper circuit in the middle (Felton et al., 2014). PSPS is a shape-memory polymer that is mechanically programmed to contract bidirectionally when heated to approximately 100 C (212 F) (Felton et al., 2014). When the layers reach this temperature, the heat stresses the material, causing it to fold. To begin the transformation of this structure the battery must first be connected. It takes around ten seconds for the heat to reach temperatures that react with the layers. The first parts of the robot that start to transform are the outer sections of the legs. As these parts fold into place in an upward movement, the body of the robot looks as though it is being raised off the ground by a string (like a puppet). When all the folds are in the correct position, it triggers the motors to lock the moveable parts in place. This then triggers another set of tabs to move into position, and the motors move again causing the parts that are already locked in place to stiffen. This motion allows the robot to stand up, and the inner legs begin to fold as the final stability feature. After all the steps have completed, the copper circuit shuts off, the system cools, and the robot structure hardens. When all the pieces of the robot are locked and stiffened, it then becomes operational (Felton et al., 2014). To see the features of this robot, refer to Figure 3, and to see this robot in motion click the provided link in the appendix. C. An Untethered Miniature Origami Robot that Self-folds, Walks, Swims, and Degrades by Miyashita, Guitron, Ludersdorfer, Sung, and Rus After the positive implications of the exoskeleton created using the origami folding technique, the MIT research team furthered their research and produced a new miniature origami robot. The composition of the layers is the same as their previous study, but a permanent magnet is placed on top of the structure in addition to the size being much smaller than the original cylindrical design. Global heating is still the means by which the PVC layer expands into the proper gaps. The change in size allows the heating process to take less time, and to be conducted on a small heating plate while still being heated uniformly. After this smaller origami robot is folded in position, it is ready to be controlled to perform functions. Unlike the robot in Felton et al. (2014) that had two attached motors, this robot is controlled by an electromagnetic coil system that creates an electromagnetic field. This platform system contains four square electromagnetic coils and when the robot is on this platform it is controlled with a joystick (Miyashita et al.,

4 2015). The user can then direct the structure to move forward, dig through objects, climb on slopes, and even swim by pressing a button or adjusting the slider on the controller (Miyashita et al., 2015). The link provided in the appendix for Video 2 details this process. Another modification to this robot is its ability to degrade in different substances. They created one model where the outer layer (structural layer) can dissolve in water and another one where the entire body can degrade in acetone (leaving the magnet) (Miyashita et al., 2015). These three approaches to the concept of an origami robot provide the foundation for an understanding of the current state of the field. The first article provided the starting point for which a structure, with calculated etchings, can take form when heat is applied. This structure is able to support movement from an inserted device that allows it to move. The following article by Felton et al. (2014) took the concept of an automated robot, but applied a heating source within the structure. They also attached their actuating device onto the 2D material before it took its origami shape which made the precision of the system all the more impressive when everything locked into place. The final article miniaturized the robot and made it move by enacting a magnetic field and controlled by a joystick. By making it smaller, we can see how this robot can be applied to areas that require precision. It is also important to note how the structures were able to degrade in certain substances. In the remaining sections of the paper, we discuss a current use of this technology as well as looking toward the future implications this technology may have on the business world. CURRENT APPLICATION OF ORIGAMI ROBOTS These types of robots are still in the developmental stages, which is evident from the limited movements and structures that have been created thus far. Since the most recent article was written (Miyashita et al., 2015), the same MIT researchers have developed an extremely practical use for these microscopic devices. Specifically, the origami robot can be encapsulated in ice, enter a person s body, repair stomach wounds, and in this case, recover and eliminate an embedded button battery within the stomach. These cases typically happen with children, and if left in the body the battery can become imbedded in the stomach wall. To rectify this with little invasion, the researchers came up with a way for the robot to enter the body, remove the battery, and then deliver medicine to the location to repair the wound. This is done with two robots, the remover and the deliverer, which are controlled with an electromagnetic actuation system (Miyashita et al., 2016). This process starts by creating a silicon mold that is in the shape of a capsule, with a hollowed out center. Water is poured into the mold then frozen. This method allows the capsule to be easily swallowed, without compromising the integrity of the structure (Miyashita et al., 2016). They then preheat the origami structure for it to fold, and then place the robot inside the capsule; and the patient swallows it. For the structure to be accepted in the human body, it must be made out of materials that are biocompatible and biodegradable (Miyashita et al., 2016). Once it enters the stomach, the ice capsule melts and the robot is guided to the location of the battery. The robot then finds the battery by magnetic attraction, and dislocates it from the inflammation site. It is then removed from the body through the gastrointestinal tract (Miyashita et al., 2016). The delivery phase is quite similar to the removal. Another encapsulated robot is sent into the body. This robot s structure has an additional layer that contains medicine to heal the

5 inflammation of the stomach left by the removed battery. It walks in the stomach and patches the inflammation site by landing on it (Miyashita et al., 2016). After this occurs, the robot s body degrades and the magnet left behind is discarded through the gastrointestinal tract (Miyashita et al., 2016). FUTURE IMPLICATIONS OF THE ORIGAMI ROBOTS ON BUSINESSES The popular opinion of robots is that they are structures that take on human-like qualities. These machines are able to perform automated tasks in manufacturing, or roll around on a set of wheels and perform tasks the users wish it to do. Origami structured robots may one day be able to perform these types of functions, which is why the techniques these researchers are developing could be so ground breaking to the robotics and business world. This is best exemplified in Felton et al., 2014, by automating the folding process, origami-inspired machines can be produced without manual folding, reducing the skill and time necessary for fabrication. Although it may take many more years of research to perfect, if the application of origami structures can be applied to bigger structures it would save money, time, physical materials, and labor. For example, because these machines are able to assemble themselves, the only labor skillset needed would be in the development of the designs, and personnel to monitor the robot as it transforms. Although more complex structures would take more time, there are already software programs being utilized in the creation of the origami robot. Additionally, there would be savings realized in transportation. Since all the origami patterns start off flat, the future 3D structure would save space and cost when being shipped or transported to its final destination. The opportunity cost with the time saved in assembly could be beneficial to smaller companies who could utilize this technology, as well as larger companies who are looking to focus their attention on their main expertise. The time required for these machines to be assembled would also be greatly reduced, as an electrical source could be attached and the machine would assemble itself. Material cost could also be reduced. The physical materials needed to make these structures are quite simple and inexpensive as explained in the production of the MIT and Harvard structures. For example, the Harvard team created their robot for $80-$100, with most of the cost coming from the motors and batteries (Spotts, 2016). Also, the whole process only requires a laser cutter machine for fabrication, but even the laser cutter can be substituted with an inexpensive vinyl cutter, thus making the process widely accessible (Miyashita et al., 2015). Even though this technique would save money in production cost, it would require more labor-intensive work. However, while there are potential cost reductions in manufacturing and logistics, it is the revenue opportunities associated with this new technology that is truly significant, specifically in areas of innovation and market creation. Because it is so early in this technology s life cycle, the business opportunity is unclear but likely vast. For instance, pop-up structures could greatly improve search-and-rescue techniques, and even be used in continuity planning for emergencies. Unfolded structures could be housed in a warehouse and if something happened, they could be transported to the site, directed to self-assemble, and used to help search areas for victims. This

6 could help officials locate those who need help more quickly, versus wasting precious time sifting through debris (Spotts, 2016). Similarly, another application of the technology is in furniture assembly. For example, IKEA could sell furniture with origami technology, thus eliminating customer assembly (Chang, 2014). Another interesting use could be with the development of satellites or robots in space. With the robot being fully automated, there would be no need for the structure to be helped during assembly, which could allow for the reduction of the risk associated with its assembly (Chang, 2014). Scientists can send up the robot in a capsule, similar to the robot that can repair stomach wounds. Once the robot releases itself from the capsule it can begin its work in environments that are too dangerous for humans. Similar to the methods used by Miyashita et al., 2016, the technology can have many applications in health care. Many of today s routine but invasive surgeries could use the miniature origami robot. For example, potential procedures that would be candidates for the use of origami robots include hernia repair, breaking down of kidney stones, screening and diagnostic tests such as colonoscopy and gynecologic exams, and even biopsies of certain organs or other parts of the body. CONCLUSION The emergence of origami robots has major implications for the business world. This technology has only scratched the surface of what it might accomplish, especially since the prototypes of the robots have only been around for three years. From the beginning of the MIT group s first design of the cylindrical exoskeleton, it has come a long way to include scaling down to microscopic robots that can enter the body to repair wounds. Even though there is currently only one realworld application for these robots, we believe there is great potential for the innovative application of this technology across industries. With creative application of this potentially scalable technology, industry will reduce costs and deliver better products. In fact, if the selfactuating pop-up structure is introduced into these different areas, we could see new, previously unimagined markets created, ultimately transforming global markets and industry. APPENDIX

7 Figure 1: Explanation of the technique used to create the layers in Miyashita et al., 2013 Figure 2: Amount of heat and time it takes for the structure to form into the cylindrical exoskeleton (Miyashita et al., 2013) Figure 3: Felton et al., 2014 design of origami robot Video 1: Felton et al., 2014 device from Figure 3, Steps A through F (link available upon request)

8 Video 2: Miyashita et al., 2015 device from being placed onto heating plate to degrading in acetone liquid (link available upon request) Figure 4: Miyashita et al., 2016: time sequence of deployment, battery dislocation, and wound patching REFERENCES Chang, K. (2014) Origami Inspires Rise of Self-Folding Robot. The New York Times, pp. 15. Felton, S., M. Tolley, E. Demaine, D. Rus, and R. Wood. (2014). A Method for Building Selffolding Machines. Science, 345 (6197), pp Hotz, RL. (2014). Self-folding Robot Based on Origami [Interview]. Retrieved from Miyashita, S., Cagdas D., and Rus, D. (2013). Self-pop-up Cylindrical Structure by Global Heating. IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pp Miyashita, S., Guitron, S., Ludersdorfer, M., Sung, C., and Rus. D. (2015) An Untethered Miniature Origami Robot That Self-folds, Walks, Swims, and Degrades. IEEE International Conference on Robotics and Automation (ICRA) pp Miyashita, S., Guitron, S., Yoshida, K., Li, S., Damian, D., and Rus, D. (2016) Ingestible, Controllable, and Degradable Origami Robot for Patching Stomach Wounds. IEEE International Conference on Robotics and Automation (ICRA) pp

9 Spotts, P. (2014) How Robots Could Assemble Themselves a La Origami--and Not Cost Too Much. Christian Science Monitor pp