Electrical Applications

**165**

**Chapter 8**

**Abstract**

based biomaterials.

**1. Introduction**

System

*Takashi Kawabata*

Proton Conductivity in Chitin

We have created and researched fuel cells using biomaterials as next-generation low-environmental-load energy. As is well known, chitin is a biomass that is discharged in large quantities as a marine product processing waste. We have focused on the chitin and have been studying the production of fuel cells and proton conductivity using it. It was revealed that chitin can be used as an electrolyte membrane for fuel cells under humidified conditions and becomes a proton conductor. It was found that the presence of water molecules is important for the appearance of proton conduction in chitin system. This study presents the utility value of chitin in new fields and provides insight into the proton conduction mechanism of chitin-

In the olden days of biomaterials, prostheses and medical alternatives have been mainly developed. However, there are reports that biomaterials play a wider range of roles today and can be used in the field of electronic devices such as sensors. In other words, biomaterials are not limited to medical materials, but are becoming more valuable than materials such as plastics and metals that we usually use.

We have fabricated fuel cells based on chitin and investigated its proton conductivity in chitin systems. It is well known that the chitin is superior biomass emitted from marine products and is obtained from crabs and shrimp shells. It is also famous that chitin has excellent biocompatibility and can be easily decomposed in the environment. For a long time, most research on chitin focused on biocompatibility and ion adsorption capacity. For example, Malette *et al*. have studied the curative effect of chitosan on the vulnerary [1]. Sandford *et al*. reported the useful substituent effect of chitosan to skin [2, 3]. Nair and Madhavan have suggested the method for the elimination of Hg in solution using chitosan, and Peniche-covas *et al*. have investigated the efficiency of adsorption of Hg [4, 5]. Recent studies seem to focus specifically on biocompatibile medical application and biomass. Romana *et al*. have suggested that chitin-PLA laminated composite becomes a candidate for medical applications such as implants [6]. Mohamoud *et al*. have shown that insects can be used as an alternative low-cost chitin source, and bio-convert chitin directly to

**Keywords:** Chitin, chitosan, fuel cell, proton conductor, electrolyte

ethanol by using strain of *M. circinelloides* [7].
