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In 2011, the National Institutes of Health established NCATS and started investing in organs on chips and other in vitro technologies. Other government funders, like the Defense Advanced Research Projects Agency and the Food and Drug Administration, have followed suit. For instance, NIH recently funded NASA scientists to send heart tissue on chips into space. Six months in low gravity ages the cardiovascular system 10 years, so this experiment lets researchers study some of the effects of aging without harming animals or humans.

Scientists have made liver chips, brain chips, heart chips, kidney chips, intestine chips, and even a female reproductive system on a chip (with cells from ovaries , fallopian tubes, and uteruses that release hormones and mimic an actual 28-day menstrual cycle). Each of these chips exhibits some of the specific functions of the organs in question . Cardiac chips, for instance, contain heart cells that beat just like heart muscle, making it possible for researchers to model disorders like cardiomyopathy.

Shuler thinks organs on chips will revolutionize the world of research for rare diseases. “It is a very good model when you don’t have enough patients for normal clinical trials and you don’t have a good animal model,” he says. “So it’s a way to get drugs to people that couldn’t be developed in our current pharmaceutical model.”

Each chip starts with a physiologically based pharmacokinetic model, known as a PBPK model—a mathematical expression of how a chemical compound behaves in a human body. “We try and build a physical replica of the mathematical model of what really occurs in the body,” explains Shuler. That model guides the way the chip is designed, re-creating the amount of time a fluid or chemical stays in that particular organ—what’s known as the residence time. “As long as you have the same residence time, you should get the same response in terms of chemical conversion,” he says.

Chip technology, while sophisticated , has some downsides . One of them is user friendliness. “We need to get rid of all this tubing and pumps and make something that’s as simple as a well plate for culturing cells,” says Vunjak-Novakovic. Cost and sourcing can also be challenging. Emulate’s base model, which looks like a simple rectangular box from the outside,starts at around $100,000 and rises steeply from there. Most human cells come from commercial suppliers that arrange for donations from hospital patients. During the pandemic, when people had fewer elective surgeries, many of those sources dried up. As microphysiological systems become more mainstream , finding reliable sources of human cells will be critical.