Wearable oxygen and conductimetric sensors were constructed by microfabrication techniques for monitoring biochemical substances. The wearable oxygen sensor (thickness 84μm) was calibrated against dissolved oxygen from 0 to 8.0mg/l, and could be used to monitor the transcutaneous oxygen pressure by applying onto the forearm skin surface. Tear fluid conductivity was possible to be measured by applying the wearable sensor to the human subject's temporal lower cul-de-sac, thus evaluating electrolyte concentration and turnover rate in tear for normal, healthy volunteers and dry-eye patients.