When exposed to gases and vapours of certain chemicals in their surrounding environments, chemiresistive materials can change their electrical resistance, which makes them incredibly useful as sensors for air pollution. Through her work, Dr Esther Hontañón, a researcher at the Spanish Council of Research (CSIC) in Madrid, explores how the latest advances in materials science and 3D printing technology can be used to enhance the sensitivity of these materials even further. Her team’s discoveries are now paving the way for cutting-edge networks of wireless pollution sensors, which could be applied in many real-world scenarios.