The microneedle patch

(Image credit: Devin McAllister, Georgia Tech)Researchers in Georgia have developed a "microneedle patch" that can deliver the flu vaccine through a person's skin. In a new study, 70 percent of people who used the experimental patch in a Phase I clinical trial said they preferred it to a traditional flu shot.

This close-up image shows the microneedles on the patch. Each microneedle is 650 micrometers (about 0.03 inches) long and is filled with the flu vaccine. The needles dissolve when the patch is pressed into the skin. [Full story: Painless Patch Delivers Flu Vaccine Through Microscopic Needles]

Microneedles, magnified

(Image credit: Devin McAllister, Georgia Tech)A more magnified image shows the 100 microscopic needles on the patch.

Applying the patch

(Image credit: Rob Felt, Georgia Tech)Lead study author Dr. Nadine Rouphael, an infectious-disease specialist and associate professor of medicine at Emory University School of Medicine in Atlanta (right), applies the microneedle patch to a study participant's left wrist.

Listen for the "click"

(Image credit: Rob Felt, Georgia Tech)To apply the patch, a person places it on the back of their wrist and presses down with their thumb until they hear a click. The click means that enough pressure was applied for the microneedles to enter the skin and start to dissolve.

After 20 minutes, the patch can be removed and thrown away.

The patch in perspective

(Image credit: Christopher Moore, Georgia Tech)Mark Prausnitz, a professor of chemical and biomedical engineering at the Georgia Institute of Technology and the senior author of the study, developed the microneedle patch with his team.

In the lab

(Image credit: Christopher Moore, Georgia Tech)Prausnitz examines the microneedle patch in the lab where it was developed.