60 / 2019-08-14 15:29:41

Bio-inspired microfluidic sweat sensor

Bio-inspired,sweat sensor,Electrochemical sensing

全体主题 > Medical diagnosis and surgical robotics

Wearable sensors have received tremendous attention for their superiority of monitoring an individual’s health. Unlike most wearable sensors that track vital signal physically, the new wearable sensors can detect bio-markers from human body in a real-time, continuous way. Human sweat is rich in many chemical components which are closely related to health status. We can prevent diseases according to the results of analyzing sweat in some cases. For example, we can know the concentration of the glucose in blood in time, because the concentration of glucose in sweat and blood are positively correlated. The concentration of lactate can be used to characterize the body's exercise intensity. Excessive lactate means the possibility of sports injuries.
However, one of the difficulties in sweat sensing is the collection of sweat. In the past, researchers used fabric to transport sweat, which is simple and low-cost. However, sweat extraction and renewal become hard for the sweat gathers in the fabric. Accordingly, this kind of sensor can’t detect the sweat precisely and sensitively.
In our past work, we revealed the mechanism of directional water transport on the surface of Sarracenia. In this work we mimic the Sarracenia trichome and fabricate a surface with many microchannels. The wall of the microchannel has many micro-thorns which lead to directional sweat harvest and transport. A Nano-porous Au electrode fabricated by de-alloying together with an Au counter and Ag/AgCl reference electrode are used for glucose sensing in sweat. Interdigital electrode is covered by reduced graphene oxide, so it can sense humidity owing to the change of resistance. With the help of microchannels, the sensor can detect fresh sweat simply and continuously.