Scientists at the Institute of Semiconductor Physics of the Siberian Branch of the Russian Academy of Sciences have created a wearable sensor and obtained a patent for it.
According to the patent documents, the device is attached to the arm and measures stress levels through the skin. Thanks to its design, the device offers increased sensitivity to cortisol concentration and other stress indicators in sweat.
According to the researchers, monitoring ongoing stress is essential for the early detection of serious conditions, making lifestyle adjustments, and maintaining mental and emotional health.
It should be noted that previously developed sensors have low sensitivity to cortisol concentration, making it impossible to accurately track changes in psychological and emotional state in real time. Furthermore, they are either technically complex and expensive, or rely on indirect indicators (such as skin conductivity) and additional components (antibodies), which reduces their effectiveness.
According to the documents, this innovation "aims to solve this problem by creating a highly efficient, inexpensive, easy-to-manufacture, technically easy-to-use resistive sensor unit that is attached to the skin to monitor changes in a person's psychological and emotional state over time, using electrical conductivity as a means to achieve this technical result."
Scientists have managed to increase the sensor's sensitivity to the hormone cortisol by using an extremely thin semiconductor layer—no more than 20 nanometers thick. This sensor records changes in the concentration of the substance more accurately and provides more reliable results than previous similar devices.
The device consists of a flexible substrate coated with a sensitive layer of a conductive composite material. This layer is composed of graphene, an organic polymer, and ethylene glycol, which reduces electrical resistance, thus increasing the sensor's sensitivity. The scientists propose applying this layer using either two-dimensional printing or distillation.
The inventors say: “Sweat contains a variety of components - 98% water, and 2% chemical compounds, including salts, oxygen, glucose, adrenaline, cortisol, dopamine, enzymes and other components. Placing the sensor node on the wrist ensures contact between the sweat secreted through the skin and the material of the sensor layer, which leads to the accumulation of charge in it, and thus an increase in the electrical conductivity of the sensor element.”
