This work presents the fabrication, characterisation and the performance of a wearable, robust, flexible
and disposable chemical barcode device based on a micro-fluidic platform that incorporates ionic
liquid polymer gels (ionogels). The device has been applied to the monitoring of the pH of sweat in
real time during an exercise period. The device is an ideal wearable sensor for measuring the pH of
sweat since it does not contents any electronic part for fluidic handle or pH detection and because it can
be directly incorporated into clothing, head- or wristbands, which are in continuous contact with the
skin. In addition, due to the micro-fluidic structure, fresh sweat is continuously passing through the sensing area providing the capability to perform continuous real time analysis. The approach presented here ensures immediate feedback regarding sweat composition. Sweat analysis is attractive for monitoring purposes as it can provide physiological information directly relevant to the health and performance of the wearer without the need for an invasive sampling approach