A recent technology that has emerged as an alternative to animal testing is known as "organ-on-a-chip" technology. Organs-on-chips, aka microphysiological systems, are small cell culture chips that mimic the structure and function of tissue, allowing researchers to study the effects of drugs on lungs, hearts, kidneys and other organs without needing an actual organ to perform tests on. The issue with the technology thus far, however, is that it's expensive and time-consuming to collect the data necessary for the chips and then to fabricate them, but researchers at Harvard University have developed a new, more efficient and more flexible method for creating them: 3D printing. Read more at 3DPrint.com: https://3dprint.com/153547/3d-printed-heart-on-a-chip/