For more than 25 years, lab-on-a-chip technology has allowed researchers to model human organs and blood vessels using real human cells in artificial microscopic environments. These microphysiological systems (MPS) may replicate human cells and mimic organs or even full organ systems under numerous conditions. They have become key to studying everything from heart disease to the effectiveness of new drugs. However, they have been held back by one major limitation: an inability to accurately re-create the blood flow waveforms generated by the human heart.