Sometime in the near future, the military may begin using tiny, dissolvable electronic devices to help wounded soldiers to fight off infection. The technology opens potentials beyond the battlefield, allowing wider use of sensors and a variety of short-term medical applications as well as providing new ways to fight infection in existing surgical implants.
Developed by the Defense Advanced Research Projects Agency, the Defense Department’s research and development shop, these “transient” electronic devices are designed to dissolve when exposed to water and can last for weeks, days or even minutes. The electronic components are made of superthin sheets of silicon and magnesium sheathed in silk. Silk is biocompatible, which means that it can be inserted safely into the body. How long a device lasts is determined by the thickness and crystalinity of the silk.
Silicon and magnesium occur naturally in the human body and because the amount of material used in the devices is so small, they are safe to use in the body and environmentally friendly, DARPA officials said.
Program scientists have also demonstrated that the devices can also be powered externally by microwaves. In a recent podcast researchers noted that the same process used to provide power could be used to retrieve data from implanted sensors, opening the possibility for dissolvable medical sensors to monitor patient health. A paper on the new technology has been published in the September 28 issue of Science.
DARPA researchers used the technology to build a device that acts as a non-antibiotic programmable bactericide that is left in the body at a surgical site to prevent infection. Once the device has done its work over the course of a few days or weeks, it dissolves harmlessly–eliminating the need for additional surgery to remove it.
“Transient electronics applied to localized antimicrobial therapy would be a major advance,” said the effort’s program manager, Alicia Jackson in a statement.
Localized infection is a constant worry faced by the current family of implanted devices such as pacemakers and artificial joints, Jackson said.
One way to counter infections in the future would be to apply a thin electronic film to a device, which would then sterilize it after it is placed in the body. The electronics could deploy anti-bacterial drugs or heat up to kill bacteria. The localized heating would only be a few degrees above body temperature, but it would be high enough to kill bacteria the same way that a fever does, DARPA officials said. This would be a very effective way to kill even drug-resistant bacteria, they added.
The dissolvable electronics would create a new way to both eliminate infections and enhance the effectiveness of many implantable devices, which would greatly reduce complications and deaths in patients, Jackson said.
Other potential applications include disposable environmental sensors for monitoring events such as toxic chemical spills. After they have completed their mission, they can be left in the field to safely dissolve back into the environment, DARPA officials said.