Sending Text Messages with Chemicals Could Lead to Communicating Medical Implants
Stanford University researchers led by postdoc Nariman Farsad have built a machine that sends text messages using common household chemicals. The chemical communication system relies on a binary code to relay messages, but instead of zeros and ones, it sends pulses of acid (vinegar) or base (glass cleaner). The researchers type their desired message in a small computer. The computer then sends a signal to a machine that pumps out the corresponding chemicals, which are sent through plastic tubes to a small container with a pH sensor. Changes in pH are then relayed to a computer that deciphers the encoded message. Farsad chose these specific chemicals because they are easy to obtain and they cancel each other out at the receiving end of the system. The researchers are currently looking into how chemical communication could advance nanotechnology. Cost-effective nanotechnology already exists that may someday go inside the human body. But these devices are so small that, in order to communicate, they have to be wired together or else depend on high-frequency signals, which could potentially cause organ damage. These signals also tend to only travel short distances and powering them has yet to be figured out. As an alternative, chemical-based data exchange could be self-powered, traveling throughout the body harmlessly - and undetectable by outside devices.
Transcript
00:00:00 {MUSIC PLAYING] Stanford University. This is a new way of sending information that's not using electromagnetic waves as most wireless systems use, but rather, using chemicals that are being transported through a medium that carry the information via the chemicals. We have several different pumps. And we control these pumps through the microcontroller.
00:00:28 So we're injecting three different types of chemicals into the channel. We're going to convert the text message into a sequence of zeroes and ones. For each bit, we are injecting either an acid or the base into the channel. So this pH meter takes the measurement. And then the measurement is sent to the computer where we do the processing for detection. One of the most exciting applications in my mind
00:00:51 is in body communications. You don't want to send electromagnetic waves through the body because it can cause damage to the tissues. It also doesn't propagate very well through the body, whereas the body is already using chemicals to communicate between cells. And so our vision is that using these chemical communication systems, we can put them in the body to have sensors talk to each other, to send signals to drug delivery systems,
00:01:16 to read devices that are in the body. There's a lot of other potential applications that this could open up. Robots could communicate through chemical tags or chemical trails and [INAUDIBLE] and in smart cities, in environments where radio does not propagate very well or it fails. We believe that we have a long way to go to make this system faster and better and more reliable. We think that even with the performance we have today,
00:01:42 it actually would work in certain applications. It's almost like going back to the days of Marconi when we were first discovering how to use radio waves for communication. I think we're first discovering how to use chemicals. In fact, I think the possibilities are endless. For more, please visit us at stanford.edu.