Tiny swallowed devices have already shown their effectiveness as a more advanced way of delivering drugs to the body and performing invasive procedures, for example, colonoscopy. The main problem of such devices is still the power supply.
Researchers at the Massachusetts Institute of Technology have developed a safe source of nutrition, where gastric acid will be used as the electrolyte. It will become part of the already developed drug delivery systems that operate within the body for several weeks.
The idea to use gastric juice as an electrolyte is easy to explain, since the basis of the electrolyte of most batteries is acid. As an experiment, scientists attached zinc and copper electrodes to the outside of a small swallowed capsule containing a thermal sensor and a 900-MHz transmitter.
Gastric acid, as it turned out, conducts electricity well between the electrodes, ensuring the operation of the device. During the experiments conducted on pigs, it was possible to record temperature readings and transmit them in wireless mode every 12 seconds at a distance of up to 2 m from the receiver.
The “journey” of the device inside the gastrointestinal tract lasted about six days. After entering the small intestine, the acidity decreased, which led to a decrease in the efficiency of the device by about 1%, but this was quite sufficient for its continued work.
The length of the device is 40 mm, width is 12 mm. The energy received is sufficient to deliver drugs wrapped in thin gold foil. As the researchers assure, in the future, as the system improves, its dimensions will decrease.