Hydrogels can play Pong by ‘remembering’ previous patterns of electrical simulation

Non-living hydrogels can play the video game Pong and improve their gameplay with more experience, researchers report. The researchers hooked hydrogels up to a virtual game environment and then applied a feedback loop between the hydrogel’s paddle — encoded by the distribution of charged particles within the hydrogel — and the ball’s position — encoded by electrical stimulation. With practice, the hydrogel’s accuracy improved by up to 10%, resulting in longer rallies. The researchers say that this demonstrates the ability of non-living materials to use ‘memory’ to update their understanding of the environment, though more research is needed before it could be said that hydrogels can ‘learn.’