Why has Joey been playing with an antarctic icefish for the last few years? These unusual creatures have developed evolutionary adaptations that allow them to survive in harsh environmental conditions, and modelling these adaptations might be the key to designing a microphysiological ‘human’ on a chip for drug discovery. Scaling presents a big practical problem in connecting organ compartments together: how do we make sure the liver has sufficient volume to metabolize a drug dose delivered through the lung surface area, to treat a cancer tumor in the GI tract? The icefish has developed natural adaptations to overcome critical transport limitations imposed by their surroundings, and Joe shows with experimental and analytical models that these ‘tricks’ may be used to design physiologically scaled humans-on-chips. Check out the publication recently out in Technology!