Figure 7.

(A) Schematic diagram of the 3D microfluidic device developed by Cao et al. for sweat analysis. Schematic representation of the device applied on skin; a channel was formed by folding the origami device through which the sweat flow from the skin to the electrochemical cell. Picture of the device applied on the forearm of a user. Reproduced from [158] with permission from The Royal Society of Chemistry. (B) Schematics of the procedure of fabrication and the final design of the screen-printed electrochemical cell inserted in the mask developed by Maier et al. (i and ii). Model of the customized filter extension in which the screen-printed electrochemical cell is inserted (iii). Photograph of the respiratory mask with the filter extension containing the screen-printed electrode (iv) Reproduced from [167] (open access).