21 February 2019
Highly sensitive wearable sensors
Published online 27 August 2015
New sensor can read even the smallest fluctuations in blood pressure and human voice.
A research team from Saudi Arabia has developed a highly sensitive and cheap wearable sensor that can detect minute blood pressure changes, making it potentially useful for signalling the onset of physiological anomalies.
It can also recognize aberrations in human voices through detecting throat muscle movements, and, reportedly, operate at a low voltage generated by a small-size battery.
Gilles Lubineau and his colleagues from King Abdullah University of Science and Technology (KAUST) first synthesized hydrogel from sodium alginate and doped it with single-walled carbon nanotubes. They then used the nanotube-doped hydrogel to make hydrogel spheres which were placed between two indium–tin oxide-coated polyethylene terephthalate films, forming the pressure sensor.
The sensor can read changes in physiological signals at rest and after exercise, the scientists say. When attached to a human neck, the sensor tracked muscle movements that were specific for different words such as ‘bang’, ‘stay hungry’ and ‘stay foolish’, suggesting its potential for voice recognition.
“Using multiple pressure sensors, it would be feasible to make a skin-like array of sensors that could map slight fluctuations in blood pressure, predicting the threats of cardiovascular diseases,” says Lubineau.
Tai, Y. et al. A highly sensitive, low-cost, wearable pressure sensor based on conductive hydrogel spheres. Nanoscale http://dx.doi.org/10.1039/C5NR03155A (2015).