Soft robotics is a relatively new field of study that has been skyrocketing in popularity. Simply said, soft robotics involves the concept of utilizing softer, more flexible materials like rubber and silicon, rather than the commonly used rigid components in mechanical devices. While it may seem somewhat counterintuitive to use elastic materials—as doing so may result in both decreased stability and strength—the increased flexibility provides distinct advantages that cannot be achieved by rigid movement. This is mainly due to the fact that plasticity is an uncommon attribute among typical machines. As a result, this idea of incorporating bendable elements into machines for increased fluidity allowed multiple breakthroughs regarding previously impossible tasks.
The first records of development in machines involving elastic attributes date back to the 1950s, when an American physicist named Joseph Laws McKibben invented pneumatic artificial muscles. Pneumatic artificial muscles, also known as PAM, were initially invented for the purpose of aiding polio patients who suffered from paralysis. Unlike the conventional actuators at the time, PAM was not only lighter, but was also more efficient and much easier to manipulate, resulting in better functionality. As a result, PAM was soon widely utilized in multiple different machine designs. Since this change in paradigm, the usage of flexible machines in various fields have increased steadily.
However, considering how it has almost been an entire century since the birth of the first soft machines, the specific concept of ‘soft robotics’ was established quite recently during the late 1990s. Even then, it was considered as a minor field that did not receive much attention from the scientific community. The fact that there were less than a hundred research papers regarding the topic of soft robotics before the 21st century effectively displays its obscurity within the scientific community. It has only been a decade or so since the field of soft robotics started accumulating more and more recognition. Beginning from around 2008, research papers regarding soft robotics increased exponentially in number, while the phrase “soft robotics” was accepted as a keyword in academic articles. Spearheaded by the most prestigious universities including Harvard University and Massachusetts Institute of Technology, publications regarding soft robotics soon dominated the robotics section in scholastic journals such as the Web of Science by 2015.
Figure 1: One of the multiple soft robot actuators that are being developed by researchers in NASA for space exploration.
Source Credit: LINK
Nowadays, soft robotics is utilized in a wide range of different fields ranging from manufacturing to medicine. One of the more novel breakthroughs regarding the usage of soft robotics was the development of more effective implants. A key issue that was common for most implant devices until now has been the body’s rejection of the implant. For instance, Fibrosis, the clotting of fibrous material around the implanted device, is a potentially hazardous side effect that is caused by such foregin body response. However, researchers from the National University of Ireland Galway, AMBER, and Massachusetts Institute of Technology discovered how this problem could successfully be solved through implementing the soft robotics technology in implants. Their study stated that the body’s response could be mitigated through creating oscillations through the usage of flexible soft robotics mechanisms. Like this example, soft robotics is slowly but steadily becoming essential for the development of various technologies focusing on the safety and convenience of humanity.
Q&A Section:
Jiwon: At the end of your article, you mentioned how creating oscillations through using flexible soft robotics helped solve the issue of the human body rejecting implants. What exactly is the logic behind this mechanism?
The implants utilize a specific actuator component named the DSR (dynamic soft reservoir), which utilizes its flexibility in order to contract and expand in a cyclical manner. This in turn causes constant fluctuations in fluid flow and nearby cellular mechanisms, which impedes the development of fibrous material on the implants.
Sally: What are the downsides of soft robotics? What limitations does it have compared to the common rigid mechanics?
Compared to rigid mechanics, soft robotics are less suitable for tasks that require sheer force since the increased flexibility of soft robotics generally translates to the decreased strength and stability.
John: Are there any other applications of soft robotics other than just surgical assistance and patient sustenance?
Definitely! Since soft robotics generally allows mechanical products to have greater flexibility and freedom of movement, it is applicable (and has been used) for a wide range of different purposes. For example, soft robotics is currently being utilized to develop not only space, but also deep sea exploration machines.
Xavier: You state towards the end of your article that soft robotics has been implemented in a wide range of fields. How has soft robotics been used to improve fields other than medicine, such as in the manufacturing industry?
Yes! Soft robotics has effectively improved multiple different fields, including the manufacturing industry. In the case of the manufacturing industry, soft robotics allowed the creation of more efficient assembly lines through the development of manufacturing machinery capable of a wider range of actions.
Eric: What do you think prevented the rise of soft robotics to happen sooner, if there was potential in the field before the 21st century?
Since the concept of soft robotics is very fundamental yet critical, I believe it has existed far before the 21st century. As stated in above, I believe the main reason was the general obscurity regarding the specific term (not the concept).
Hannah: Are there any significant differences between soft and rigid robotics other than the materials used?
While soft and rigid robotics are not limited in terms of material usage, nor divided simply due to the difference in utilized materials, it must be noted that some materials tend to be more frequently used in soft robotics and others more in rigid robotics. For example, elastic materials such as silicon and rubber are utilized much more often in soft robotics compared to rigid robotics.
Josh: How will soft robotics change the field of robotics for the future? What are some pros that “rigid robotics” still holds over soft robotics?
Soft robotics has completely transformed the field of robotics when it was first introduced to the world. Since then, countless impactful inventions and creations have been developed using soft robotic components. Soft robotics will continue to remain an irreplaceable aspect of robotics that removes barriers, such as the limitation of mechanical movement. However, as mentioned in the question, “rigid robotics” will remain essential in terms of not only its fundamental nature but also its situational advantages over soft robotics, such as greater strength and solidity at the cost of inflexibility.
Works Cited
Alici, Gursel. "Softer Is Harder: What Differentiates Soft Robotics from Hard Robotics?" MRS
Advances, vol. 3, no. 28, 5 Feb. 2018, pp. 1557-68. Springer, doi:10.1557/adv.2018.159.
Accessed 20 Mar. 2021.
Bao, Guanjun, et al. "Soft Robotics: Academic Insights and Perspectives through
Bibliometric Analysis." Soft Robotics, vol. 5, no. 3, June 2018, pp. 229-41. Liebert
Online, doi:10.1089/soro.2017.0135. Accessed 20 Mar. 2021.
"Soft Robotics Breakthrough Manages Immune Response for Implanted Devices." MIT
News, Massachusetts Institute of Technology, 4 Sept. 2019, news.mit.edu/2019/soft-
robotics-breakthrough-manages-implanted-devices-immune-response-0904. Accessed
20 Mar. 2021.