Some people start down their career path at a young age, and toys can often be the catalyst. To entice kids into the field of microbiology, scientists at Stanford have developed a DIY smartphone microscope that lets users take a closer look at the microscopic world and allows microbes to be controlled in real-time so they can be used to play games like soccer or Pac-Man.

Oddly enough, this isn't the first time Pac-Man has been recreated on the microscopic scale. Earlier this year, scientists at the University College of Southeast Norway built a 1 mm-wide neon replica of the iconic game's map and populated it with microbes. But while that was designed to show the cells moving independently about a 3D environment, the Stanford team took a more interactive approach.

Named after the Latin word for "play" or "game", the LudusScope lets users play and interact with the microscopic world, rather than just observe it. Like the Norwegian study, single-celled Euglena take the starring role, but this time they can be controlled by activating LEDs that the microbe will move away from. Through a few rudimentary games or unstructured play, users can learn about the organisms and, through assembling the microscope, get a crash course in electronic circuits.

"Many subject areas like engineering or programming have neat toys that get kids into it, but microbiology does not have that to the same degree," said Ingmar Riedel-Kruse, an assistant professor of bioengineering. "The initial idea for this project was to play games with living cells on your phone. And then it developed much beyond that to enable self-driven inquiry, measurement and building your own instrument."

The Euglena are housed inside a microscope slide surrounded by four LEDs. Since the microbes are negatively phototactic – meaning they move away from intense light – activating the LEDs with a joystick allows players to effectively steer the organisms, and the whole scene can be watched on a smartphone placed into the top of the LudusScope.

Using those pieces, the researchers created a Pac-Man-inspired game, where players select one of the microbes and guide it through a maze to collect dots by activating the lights in sequence. A basic version of soccer is playable too, where the Euglena are guided towards the goals, where the ball can be shot with the press of a button.

Both modes include information on the microbes and their environment, like their movement speed and scale of the image, to make the games a little more educational, or the game aspects can be done away with completely to let students focus on gathering and studying various data.

Beyond the microbiology lessons on offer, the LudusScope is designed as a DIY kit to get kids building. The whole structure is 3D-printable and easily assembled, while wiring up the lights and joystick is a relatively simple circuit that teaches several fundamental lessons in electronics. It's probably beyond the scope of a kid's solo craft project, but the kit is designed more for use in classrooms.

Creating a commercially available science kit is a goal for the team over the next year or so, which they intend to do with the input of teachers and students.

The research was published in the journal PLOS ONE.

The Pac-Man game (top) and the soccer game (bottom) can be seen in the videos below.