In 2014, Disney released the movie Big Hero 6. Set in an urban city, its central protagonist was Baymax, an inflatable medical robot. The movie gained wide recognition, mostly because of its role in the introduction of the concept of soft robots to the masses. These are not that new of an idea, in fact, soft robots have been around for quite some time. The coming of Big Hero 6 simply made their existence more noticeable.
To start off, let us address the rudimentary question first: what exactly are soft robots? Well, according to wikipedia, “Soft robotics is a subfield of robotics that concerns the design, control, and fabrication of robots composed of compliant materials, instead of rigid links.” To translate this into comprehensible words, soft robots can be made of substances such as inflatable materials and bendable plastics among many more. The basic idea of these flexible machines is to reduce the number of joints and incorporate the ability to change its shape and size on will.
Let’s take an octopus for example. Octopuses can fit through extremely small holes. How? Well, for one, they don’t have any bones. Yes, you read that right. Octopuses are highly intelligent creatures, ones that can manipulate the shape of their body to fit through the tiniest of hindrances. Thus, we can compare octopuses with soft robots based on the similar design principle that both of them follow. Soft robots can also change their build freely in order to achieve higher versatility.
Soft Robots or bending machines are also professionally called compliant mechanisms. They usually surpass traditional mechanisms in various domains. Some of the numerous advantages are listed below:
Part Count Reduction of the number of parts used is a primary gain. The utilization of flexible parts instead of other rigid counterparts like hinges allows a significant decrease in the number of fragments.
Productions processes Compliant mechanisms are generally easier to produce as they have a relatively lower number of parts and hence not much assembling is required. They can often be 3D printed, machined, stamped, laser cut or water-jet cut. They offer great variety.
Price Mainly due to simple manufacturing processes and comparatively lesser need for parts, compliant mechanisms can be very cost effective or inexpensive.
Precise motion One of the downsides of traditional mechanisms is that they can lose precision due to backlash and wear. They get their motion from physical pins and hinges sliding against one another and this eventually causes damage to the machine. This issue is tackled in the use of compliant mechanisms. They can allow precise motion by reducing attrition. Since compliant mechanisms use bending parts instead of traditional hinges they can avoid battering which would not have been possible otherwise.
Performance Compliant mechanisms don't need lubrication. This is seen as a huge benefit in harsh environments or places where machines are not accessible easily. Traditional mechanisms on the other hand require lubrication for proper functioning. In grating surroundings like space, lubricants evaporate, and cannot be replenished easily. Thus compliant mechanisms have an upper hand there.
Proportions Another function of compliant mechanisms is that they can easily be miniaturized. The reduction in the total number of parts and joints offered by them is a significant advantage in the making of micro mechanisms.
Portability Compliant mechanisms are much more compact, lightweight and portable compared to their traditional counterparts. This is very helpful in large businesses and the aerospace industry.
Predictability Last but not the least, compliant mechanisms are predictable. Even if one starts using one of these after a decade it would still work the same- as good as it was the first day it was used.
With various fields of robotics under microscopic view, the focus is mainly on expanding the possibilities and taking inventions to the next level. Therefore, it is safe to say that the era of soft robots is here- and this time, it is here to stay.
Source: Derek Muller, Jonathan Hopkins and compliant mechanisms
