The race to build a real-life tricorder

Tatiana Rypinski is maybe two bites into her salad when she realizes it???s time for her next meeting. She gets to her feet and heads to the Biomedical Engineering Design Studio, a hybrid of prototyping space, wet lab, and machine shop at the Johns Hopkins University???s Homewood campus, in Baltimore. Rypinski and a few of her colleagues gather near some worktables with power outlets dangling from the ceiling. A tool cart is in one corner, a microscope in another. Two 3-D printers sit idle along a wall. The students have agreed to meet me here to discuss their work on a project whose goal is not just inspired by science fiction???it actually comes straight out of "Star Trek." They want to build a medical tricorder.