Biological games

Pac-Man of the microscopic world

The following is from the second issue of BioCoder, the quarterly newsletter for synthetic biologists, DIY biologists, neurobiologists, and more. Download your free copy today.


If you have ever played fetch with a dog or hide-and-seek with a particularly crafty cat, then you have played a biological game. In fact, humanity has a long and morally complex history of games and rituals involving other organisms, from the bull leapers of the Minoan civilization to the chariot races of ancient Rome. Now, through the application of biotechnology, such games are beginning to extend into the microscopic world, illuminating new opportunities for entertainment, education, and the understanding of ourselves as ethical and social creatures within the larger community of life.

It was about a year ago that I first heard the term “biotic games” during a workshop at Genspace exploring the research of Stanford’s Dr. Ingmar Riedel-Kruse, in which unicellular paramecium are manipulated via electric currents in order to play Atari-style games such as Pac-Man and Pong. Dr. Ellen Jorgensen and computer engineer Geva Patz demonstrated this behavioral response to electricity, known as galvanotaxis, by placing paramecia in an area bounded by four electrodes—as one of the electrodes became negatively charged, the paramecia swam in its direction, only to make a u-turn as this electrode became positive and another negative. This immediately sparked in my mind the wonders of the 1982 landmark film Tron (which, in turn, was inspired by Pong): beings in the machine, tiny organisms living out their own lives, yet contributing to a grander process.

Having spent many years developing games and interactive media, both for computers and mobile devices, the potential impact of this technology became quickly apparent to me—not just in gameplay, but also in terms of possibilities for living, interactive art projects as well as interesting social commentary. Much has been said, for instance, about the relationship between the player of a game and his avatar within the game: do you control the avatar, or do you become the avatar?

What does it mean if your avatar is actually another living organism? The incorporation of life into gaming also has the potential to promote thoughtful reflection about humanity’s relationship to nature and the prospect of interspecies cooperation, working to combat the stigma of dehumanization and desensitization commonly attributed to video games in general. Other members at Genspace were of similar mind, and together, Dr. Oliver Medvedik, cofounder of Genspace, Sarah Choukah, Genspace member and PhD communications student, and myself decided to pool our respective expertise in biology, microcontrollers, and game development to take this technology to the next level.

The first design decision we made was to use an iPhone as the game platform (see Figure 9-1), unlike Dr. Riedel-Kruse’s original model, which relied on a desktop-based Adobe Flash interface. We made this choice both because we wanted the unit to be portable, and because we felt that having the game run on such a ubiquitous device would make the underlying technology more real to the populace, rather than just a scientific curiosity. This approach was not without its drawbacks, however, as the intense graphical processing required to motion-track multiple paramecia is difficult to pull off on relatively limited mobile platforms. While I was thus busy trying to wrangle the iPhone to this purpose, Oliver and Sarah had their own hands full with engineering the control mechanism. Complicating our respective issues was the fact that the 2013 World Science Festival at Innovation Square was set to begin just one week after we had embarked on our project, and we really wanted to present.

Figure 9-1. iPhone with microscope attachment positioned above paramecia stage

Figure 9-1. iPhone with microscope attachment positioned above paramecia stage

Sometimes science is conducted in an orderly manner, with lab coats and latex gloves, and sometimes science is conducted frantically into the wee hours over half- eaten boxes of pizza and flashing LED lights. This was the latter. But it had worked—after a solid trifecta of all-nighters, we possessed an operational prototype. Using barely more than electrical contacts and assorted Lego blocks, Oliver and Sarah had created a basic joystick, which was then connected to an Arduino microcontroller (see Figure 9-2). The Arduino, in turn, was connected to the electrodes bounding the paramecia stage, controlling them based upon the input of the joystick. Above all of this, on a platform constructed of equal parts wood and rubber bands, hovered the iPhone, with its camera augmented by an affordable microscope attachment and trained upon the paramecia stage. As the paramecia moved, my code employed a careful combination of graphical filters to track their motion, and based upon this data generated a game similar to Pac-Man, in which the microorganisms collected Tron-like discs. There was still a kink or two to work out, such as the contacts between the Arduino and the paramecia stage becoming loose and impairing joy- stick control, but it was nothing we couldn’t smooth out, we thought, during setup at Innovation Square after a good night’s rest.

Figure 9-2. Arduino code controls voltage of the electrodes based on input of the joystick

Figure 9-2. Arduino code controls voltage of the electrodes based on input of the joystick

Oliver has described what followed as performing a magic trick for the first time live and hoping you don’t saw an audience member in half, which I find both hilarious and entirely accurate. In addition to our little joystick problem being not so little (thanks in part to the throng of grasping children’s hands), the elements at the outdoor festival had conspired against us—the June heat was causing the iPhone to overheat as well as threatening to evaporate the liquid in which the paramecia were swimming, forcing Oliver and Sarah to perform continual water bottle and ice pack triage. Additionally, strong gusts of wind were causing noise in the motion detection, requiring me to tweak the code constantly in real time to keep things running smoothly. All this combined with fielding hundreds of questions, as well as managing dozens of paramecia-controlling gamers, makes for one hectic day. In the end, however, it all came together. Adults and children alike were fascinated by the concept of playing with microorganisms, and many even suggested that we launch a Kickstarter so they could buy such a system for home use. They praised the retro-graphical style and chiptune music created for the game and gave us myriad suggestions for improvements such as a central electrode to gather paramecia together—illustrating how even children can contribute to fields such as biotechnology if given the chance. In short, the response was incredible; our magic trick had worked.

Emboldened by the successful proof of concept, we have continued to work on our prototype. By the time we presented at NYC Resistor’s 2013 Interactive Show, for instance, we had laser-cut a clear acrylic housing, solving the wind problem while still allowing viewers to glimpse the system’s internal workings (see Figure 9-3). The knowledgeable hosts and audience members at this event even helped us solve our heat problem on the spot with an appropriately sized heat sink, giving just one example of the utility of atelier-style hacker spaces such as Resistor and of the Maker movement in general. At the most recent event we attended, Maker Faire 2013, we showcased the addition of an arcade-style tilt feature, which prevents an accidental (or intentional) bump of the device from skewing the game in the player’s favor. What has remained constant throughout every venue, however, is the overwhelming interest and enthusiasm people have expressed regarding this technology. This paves the way for our team and others to move forward with new and interesting applications—massively multiplayer online games in which people communicate with one another via other living creatures, self-reflexive systems in which organisms control themselves in ways they never have before, generative musical applications in which the composers are single cells…

Figure 9-3. Arduino, paramecia stage, and heat sink within clear acrylic housing

Figure 9-3. Arduino, paramecia stage, and heat sink within clear acrylic housing

It is not just in the realm of entertainment that this technology has application, but also in provoking thoughtful dialogue regarding ethics, free will, and what it means to be human among the various forms of life that inhabit our world. This was clearly driven home to me when I was asked by a young girl if it hurt to control the paramecia, and if their movement was choice or compulsion. To her first question, I was happy to answer no, as paramecia do not have nervous systems, but as for her second: that answer is not so simple. Would not the traffic flows of human beings to a city in the morning and away from it in the evening look like a compulsion, too, from a suitable distance? Even if a paremecium’s galvanotaxis nothing but a consequence of ion channels reacting to voltage gradients, is this really that different, in terms of free will, than electrical impulses traveling throughout a brain?

It is my hope that our game and others like it will go beyond even these questions and invite people to consider a future where we find a way to cooperate with organisms of every scale. Such an approach, characterized by partnership with—rather than subjugation and destruction of—nature has the potential to foster the sustainable future all of us want and can achieve.


biocoder-2014winter-142Curious about ghost hearts, garage lab safety, DNA origami, and the Enlightened Renaissance? The second issue of BioCoder is now available. Download the quarterly newsletter for DIYbio, synthetic bio, and more for free. Read it, share it with a friend, and join the biotechnology revolution.

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