Novel bio-electronic devices have a great potential for gathering biological information such as vital signs, cell behavior, protein and DNA molecule concentrations. The book presents concrete examples and shows that there are lots of sensing targets still remaining to be handled. Organic materials offer high sensitivity, flexibility and biocompatibility, and can be prepared by novel fabrication methods such as printing and coating at low cost. Part 1: OFET-based sensors. Part 2: Graphene-based materials and sensor device applications. Part 3: Applications of bio-sensing technologies, inkjet printing, tests for stroke monitoring, etc.