Soft Robots Taught Me How to Be Strong

This is Better Living Through Chemistry, a column by Ariana Remmel on how atoms and molecules can help us explore our lives.

Imagine an octopus that can fit in the palm of your hand. Except you realize this is not a living cephalopod—he is made of translucent silicone, veined with carefully etched channels that course with colorful liquids. The little beastie raises his tentacles toward the sky before gently lowering them back to your open palm in a meditative dance. He is untethered, like a puppet without strings, and you wonder if perhaps he is alive after all. No rigid components give away his robotic programing. But he is just that: a robot. In fact, he is the first self-contained, self-powered, entirely soft robot. His name is Octobot.

When I first learned about Octobot, I was a graduate student trying to design my own gel-like soft material using polymers, molecules named for their long chains of repeating units. I had always thought polymers useful only for making hard plastics, like the kinds found in milk jugs and auto parts; polymer chains tangle together and form crosslinks that make the material sturdy and unyielding. But those molecular strands can also form spacious networks of microscopic tunnels and pores that lend the material a squishable constitution, like silicone. Like Octobot.

Though Octobot could not yet walk or crawl, jump or grab, his delicate gestures were the first step toward a new generation of robot explorers. Soft robots like Octobot may one day explore parts of the planet inaccessible to their rigid counterparts, freely swimming through the darkest reaches of the deep ocean, where the crushing weight of the water column buckles human bones and steel alike.

Octobot’s hypnotic dance, so alien compared to the brittle glass and gleaming metal of my research laboratory, felt like an assurance that there would be room for softness in my work too. And though my research project lay far afield from robotics, I felt Octobot proved that soft materials can also lead to and represent innovation in technology.

That was the first of three lessons I learned from Octobot. It would be nearly five years before I was ready to hear the next.

*

The utility of softness came as a surprise because I had spent so much of my life seeking the opposite. While I never aspired to strength in any physical sense, what I wanted more than anything was sharpness and fortitude, traits rarely associated with gelatinous invertebrates.

This driving need came out in full force during a middle school science competition, where teams of students were tasked with building the tallest tower possible in forty-five minutes using pasta and glue. I made tight bundles of thin noodles to construct the tower’s base, carefully balancing the structure's ever-growing weight. For a moment, I imagined my spaghetti edifice touching the sky. But the tower began to teeter, accompanied by the sound of tiny pops in the substructure. I panicked. A catastrophic crack rang out as a load-bearing bundle exploded, shards of splintered pasta raining down at our feet.

We came in last place.

As a child, I had a hard time disentangling the crisp snap of dry pasta from the brokenness I felt around my failure to prove my worth in competition. As I grew older, that feeling of shame echoed through every perceived shortcoming. In a lonely, brutal world, I felt that a steely disposition was key to any hope for happiness, which I believed could only come from professional success. So I didn’t blame the brittle pasta for my construction mishap; I resented my own faintheartedness. It was my lack of intellectual fortitude, I thought, that caused my resolve to fracture like so much dry spaghetti.

The strength of soft materials is not measured in terms of hardness like steel, but in viscosity and elasticity: how well the substance flows; how easily it recovers.

As children, we built with spaghetti, but the iconic edifices and grand machines of the world are made of steel. I, too, wanted to be made of steel—a material ubiquitous in the built environment because of its phenomenal physical properties. Steel is primarily composed of iron mixed with other elements, such as carbon and chromium, packed together in different orientations to make the alloy hard enough to resist impact and strong enough not to crack under stress. I began the task of hardening and sharpening my intellect so that I might become the kind of person who has “a mind like a steel trap,” a term I heard adults use to describe both scientific geniuses and world leaders.

In the same way that a blacksmith heats steel to sculpt the metal and reorder its atomic structure, I imagined that my mind could be reshaped by walking a path of fire. I pushed myself to my limit, then tried to go that little bit further. I spent my high school free period locked in a dark microscopy lab documenting fluorescent C. elegans worms for independent study. My college literature requirement was met with courses in three different languages. The measure of my success came in fellowship opportunities and glowing letters of recommendation.

But there is something miserable about being forged under pressure. The constant hammering is exhausting, and I learned to dread the heat. My love of learning was tempered by an anxiety that made me seize up at the slightest hint of failure. I worried that the constant pressure was making me rigid, brittle. It seemed only a matter of time before I shattered.

*

Octobot wiggled their way back into my life during my first pandemic fall. (I’d come to regard my favorite automaton as a muse who defied any attempts to assign them a single gender, so their pronouns changed with every glimpse.) Circumstances in my own life made me recall the aspirational deep-sea explorer I’d met years before. After a year spent transitioning from research chemistry to journalism, I landed my dream fellowship as a reporter for a chemistry magazine and was hungry for recognition.

But I also felt burned-out, and guilty for being so tired. And I was lonely, which seemed further evidence of my weakness. I bemoaned my faltering focus. I felt like I was sinking into a deep, dense darkness, the weight of the world bearing down on me. Whatever steely resolve I had left was crumpled like so much paper.

Enter Octobot’s second lesson, one that applied to my self-perception as much as it did to my career. Rather than sinking to the bottom of the sea alone, I imagined I was accompanied by Octobot’s soft body, so perfectly suited to bear the forces of darkness and depth. I imagined trying to squash Octobot’s soft body within the vise of my closed fist and feeling their tentacles straining to squeeze through the cracks between my fingers. But no matter how hard I clamped down on my muse, the bitty bot’s parts always snapped back to their normal position as soon as I opened my hand. They resumed their dance as if nothing had happened. How could this little robot be so strong? The diminutive bot’s eight arms waved at me silently in answer, four at a time.

The strength of soft materials is not measured in terms of hardness or ductility like steel, but in viscosity and elasticity: how well the substance flows; how easily it recovers after deformation. These materials squish and compress under pressure, then rebound to their original shape when the force is removed. They represent a different kind of strength—a strength better suited to an environment where steel would rust and falter.

What if my efforts to harden myself to the tragedy of the pandemic, alongside the breakneck pace of my work, had become untenable and counterproductive? I scanned my mind for points of rupture, probing the broken edges for signs of tenderness laid bare. Perhaps my wandering focus could be better understood as a suppressed curiosity, like my vision of Octobot all scrunched up in my hand. Perhaps my loneliness was actually a symptom of my squelched desire to work collaboratively as part of a team. If I could recast my flaws as the early signs of needs unmet, then I could look at my misery as a state of compression that was not irreparably broken, but in need of rest. My untapped strength was not in being unbreakable, but in being softer, more elastic—capable of absorbing force in the moment and bouncing back unscathed.

*

Despite my muse’s tutelage, January 2021 undid all my work. In the span of a month, I lost my abuelo to cancer, an aunt to Covid, and a cousin to suicide. Despite the effort I had put into maintaining work boundaries and prioritizing rest, I splintered. It did not matter if my strength had once been hard or elastic, rigid or soft. The damage felt irreparable. What good had softness done me if I could still be damaged so thoroughly?

Thus began my third and final lesson from Octobot. It has been years since Octobot made her debut in milky silicone. Yet just last year, a group of scientists created a new soft material by tinkering with the proteins that make up the serrated teeth lining the suckers of squid tentacles. The researchers engineered a new biopolymer and crafted soft actuators (components used for functions like gripping and lifting) that look like hollow coins, which can be inflated and deflated on command. These new actuators are specially designed to resist the wear and tear that comes from repeated movements common to machines.

Feeling broken is not a fatal flaw. Just as new soft materials can repair themselves, I have the strength to mend myself.

What’s more, the soft protein-based gel can heal its own small tears and punctures with the help of just a bit of heat: A burst of warmth allows the severed biopolymers to tangle among themselves without any trace of a weakened scar. This, the authors said, could give the actuators a longer life of labor within soft robots, making them more resilient.

I return to my memories of Octobot, created from rudimentary silicone, and imagine this synthetic cephalopod was instead made from the reimagined organics of living flesh. She guides me back toward the inky depths, the pulsing colors of her etched veins filling the balloon pumps of her arms. She no longer dances with the artificial gesticulations of that first video, but moves with a fluidity that more closely imitates life. At first, there is only darkness and panic, then the glimmering of bioluminescence from creatures big and small. I am afraid to reach out and touch these shimmering apparitions—they appear so fragile and dainty and beautiful, these iridescent dreams that flutter like the heart of a child who believes they can enter heaven on a tower of spaghetti. I cannot bear to see them harmed.

For much of my life, I have believed that the worst thing that could happen to me is to be broken—that any fracture means failure, and that failure means ruin. I tried to harden myself against damage, and when that no longer worked, I tried to soften myself to better tolerate the blows I would be dealt. My first two lessons in softness had been meant to bolster my own resilience so that I might shore my defenses against breaking.

Yet I had fallen short. I had not learned how to heal, at least not with any sense of purpose. In thinking that brokenness was irredeemable, I had not given myself permission to consider what it would mean to put the pieces of my life back together after I shattered. And I was always going to shatter.

The last lesson Octobot taught me was that feeling broken is not a fatal flaw. That just as new soft materials can repair themselves, I have the strength to mend myself, to learn to rebuild the tangled bonds of a life that can adapt to the forces that bear upon it.

*

It seems curious that it took so many iterations for me to learn these truths from a robot when much of this knowledge was already present in my own body, which comprises a spectrum of hard and soft materials. The supple padding of my fatty tissue provides energy for muscles that alternate between rigid contractions and relaxed elongation. Bundles of muscle fibers tug on the joints that articulate the dancing movements of my skeleton: each bone a matrix of living cells and trapped minerals. My bones, the hardest components of my being, began in the womb as a squishy scaffolding of cartilage before the structure calcified to the solid strength of a femur or cranium or molar. The first step to healing a broken bone is to retrace the connections in soft sinews that join the hewn halves into a reunified whole.

It likely took a robot to teach me the utility of softness because I was only ever looking for utility. I had pursued mental fortitude, efficiency, and strength in service of greater knowledge about the world and my place in it. I sought a more perfect productivity. But now I see the error of my ways. My softness is mine, and mine alone, and my body has contained its own lessons in softness this whole time.

I still think about Octobot. I watch the video of her eight arms waving, as if to say goodbye. Soft robots will always remind me how much easier it is to muster the courage to explore the unknown when you honestly believe that you will survive whatever damage may lie ahead—or below.

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