Researchers at the University of Illinois at Urbana Champaign in cooperation with Northwestern University have found a way to stitch normal electronic components on a plastic bandage that can stick on skin, like a normal patch.
There are several studies on creating flexible electronics and I have posted news on several of them. Here the researchers are taking a different tack: using normal electronic components (that are available and very cheap) and mount them on a plastic layer with special connections that can bend so to adapt to skin movements.
The connections look like origami so that they can be stretched when the patch bends. They are embedded in two layers of plastic that are filled with a fluid (using the microfluidic approach). The chips are placed with the pins in contact with this inner fluidic layer where the wiring is sandwiched.
The advantage of having a patch "glued" on the skin is that it moves with the skin so there is no relative motion between the sensors and the body, which is the case with sensors embedded in a wrist band. Here the relative motion introduces noise that affect the quality of the signal. By glueing several patches in different parts of the body it is possible to detect complex variations and perform a much more accurate analyses, like detection of the onset of Parkinson disease before the person shows any symptoms. A test showed that the signal accuracy compares to the one of a professionally executed EEG and EKG performed in the doctor's studio.
The person does not perceive the patch(es) and this is important for monitoring stressful conditions, including insomnia, where the perception of a monitoring device would alter the result of the monitoring.
The patch is wirelessly powered, there is no need to charge it.