Tissue chips are engineered microsystems that represent units of human organs such as the lung, liver and heart modeling both structure and function. The chips merge techniques from the computer industry with modern tissue engineering with combining miniature models of living organ tissues on a transparent microchip. Ranging in size from a quarter to a a house key, the chips are lined by living cells and contain features designed to replicate the complex biological functions of specific organs. Ultimately, this new technology aims to make drug development and toxicology screening more reliable because the tissue chips may provide researchers with insights into predicting more accurately how effective potential drugs would be in humans. This could save money and resources because it would shorten the time it takes for a promising drug candidate to reach clinical trials.