Organs-on-chips are small devices that mimic the functions of human organs using living cells. These chips are designed to replicate the structure and behavior of organs like the heart, lungs, or liver, allowing researchers to study how diseases affect these organs and how they respond to drugs. By using microfluidics, scientists can control the flow of fluids through the chips, simulating blood flow and other bodily functions. This technology provides a more accurate model for testing treatments and understanding diseases compared to traditional methods, potentially leading to better medical outcomes and reduced reliance on animal testing.