University of Michigan experts say inventions such as cell phones the size of earpieces and invisible sensors to detect toxins are close to reality.

The researchers say they have figured out how to build wireless systems even smaller. while still retaining range and power efficiency.

One obstacle to further shrink small wireless devices has been trying to fit all the components onto one chip. But U-M researchers have built a tiny silicon-compatible antenna and frequency resonator that will do just that.

The antenna and resonator are two of the most problematic components in wireless systems because they require large amounts of space off the chip, thus limiting how small a device can be built, said Kamal Sarabandi, director of the radiation laboratory department in electrical engineering and computer science.

His research group developed the antenna, which is being studied for use in environmental sensors, but could be applied to cell phones, laptops and other wireless devices, said Michael Flynn, head of the wireless interface group.

We could have cell phones almost the size of an earpiece, Flynn said. You could have sensor nodes that are almost invisible, you could just sprinkle them around.