Electrodes measure the electrical current in an organism. But for the chemicals coming in and out of creatures, a new sort of device is needed that can monitor chemical pathways entering and mixing inside cells. Researchers at the University of Chicago have created such a device, which they call a chemistrode. The tiny V-shaped gadget, which is already under patent review, traps chemicals in water droplets and analyzes them. Applications for the device might include diagnosing neurological diseases that rely on chemical pathways and studying how living tissue responds to chemical stimulation.