Hydrogels Can Learn To Play Pong

An anonymous reader quotes a report from Ars Technica: Pong will always hold a special place in the history of gaming as one of the earliest arcade video games. Introduced in 1972, it was a table tennis game featuring very simple graphics and gameplay. In fact, it’s simple enough that even non-living materials known as hydrogels can “learn” to play the game by “remembering” previous patterns of electrical stimulation, according to a new paper published in the journal Cell Reports Physical Science. “Our research shows that even very simple materials can exhibit complex, adaptive behaviors typically associated with living systems or sophisticated AI,” said co-author Yoshikatsu Hayashi, a biomedical engineer at the University of Reading in the UK. “This opens up exciting possibilities for developing new types of ‘smart’ materials that can learn and adapt to their environment.” […]

The experimental setup was fairly simple. The researchers hooked up electroactive hydrogels to a simulated virtual environment of a Pong game using a custom-built electrode array. The games would start with the ball traveling in a random direction. The hydrogels tracked the ball’s position via electrical stimulation and tracked the paddle’s position by measuring the distribution of ions in the hydrogels. As the games progressed, the researchers measured how often the hydrogel managed to hit the ball with the paddle. They found that, over time, the hydrogels’ accuracy improved, hitting the ball more frequently for longer rallies. They reached their maximum potential for accuracy in about 20 minutes, compared to 10 minutes for the DishBrain. The authors attribute this to the ion movement essentially mapping out a “memory” of all motion over time, exhibiting what appears to be emergent memory functions within the material itself. Perhaps the next step will be to “teach” the hydrogels how to align the paddles in such a way that the rallies go on indefinitely.