There has been a notable trend in storytelling toward the redemption of beings that were once considered purely evil. In fantasy, for example, dragons have evolved from simple, violent animals into noble beasts, often of near- or above-human intellect, who act as helpers of humanity or as heroes in their own right. In science fiction, we’ve seen a similar shift in the purpose and personality of robotic characters.

In her article in the April 2019 issue of MRS Bulletin, Hortense Le Ferrand, recipient of the 2018 MRS Bulletin Postdoctoral Publication Prize, connects the emergence of benevolent robots to “the use of soft materials, characterized by conformability, colors, and constant adaptation to the environment.” A recent example of this new, benign model of a robot is the soft, white, inflatable Baymax, featured in Disney’s 2014 movie Big Hero 6, whose original purpose is to provide medical treatment with a kindly bedside manner and who eventually dons the mantle of superhero.

Soft robots are conformable and potentially self-healing and self-actuating. Their materials can often be 3D printed, and the number and diversity of these materials allow for wide customization of shape and functionality. Taking full advantage of these strengths will, however, necessitate further innovation in areas such as locomotion, environmental resistance, resilience, lifetime, and energy consumption. Even Baymax requires the support of a “carbon fiber skeleton,” and after he becomes a superhero he wears a mecha-like outer shell that grants the additional strength and resilience needed for his new, more physical duties.

With the help of stiffer composite materials that “combine the benefits of soft robotics with the performance of traditional hard metallic robots,” the need for Baymax’s internal skeleton might be mitigated. Carbon- and ceramic-based materials can be used to fortify softer materials, and in doing so provide benefits such as increased stress and loading potential, reduction of environmental sensitivity, and augmented resilience to “external mechanical damage.”

Of course, robots made with composite and multiple materials must overcome their own unique difficulties in order to reach their full potential. Compared to purely soft robots, composite robots are limited in the areas of self-actuation, autonomous response to external stimuli, and printability. Discovering and implementing solutions to these complications is a challenge encompassing many disciplines that promises a bounty of new, life-improving technology. As Le Ferrand points out, “Optimization of both the manufacture and control of composite-based robotic systems could lead to the design of robots that could not only replace humans in certain tasks, but also in applications where humans are underperforming, such as for rescue and exploration.”

The final types of materials explored in Le Ferrand’s article are those composed of living cells. These may be able to fill the needs of “the ultimate autonomous robot,” one that can “wander on its own in any environment.” Such a creation would require some form of energy source and the ability to self-grow, both of which—with a little help from a steady supply of nutrients—can be found in living cells.

Ultimately, Le Ferrand emphasizes, “the interest in robotics is not to replace nature and humans, but rather, to be used in areas that are dangerous or undesirable to us.” Composite robots present a future that is in contrast to science fiction’s often dour predictions of world domination by harsh, metallic overlords. In this brighter future, just as the addition of stiffer materials expands the capabilities of soft robots, so will autonomous composite robots expand humanity’s possibilities beyond what our biological makeup can handle.

Read the full article, Robotics: Science preceding science fiction, by Hortense Le Ferrand in MRS Bulletin for free until July 31, 2019. MRS Bulletin is a joint publication by the Materials Research Society and Cambridge University Press. Please click here to find out more about the journal.