Piezoelectric properties biopolymers

Odd-numbered nylons, the next most widely investigated semicrystalline piezoelectric polymers, have excellent piezoelectric properties at elevated temperatures but have not yet been embraced in practical application. Other semicrystalline polymers including polyureas, liquid crystalline pol5oners, biopolymers, and an array of blends have been studied for their piezoelectric potential and are summarized in the following section. The chemical repeat imit and piezoelectric constants of several semicrystalline pol3uners are listed in Table 3. 

Starting from these initial studies, a Urge number of works have been published on the piezoelectric properties of biopolymers of both natural and synthetic origin. This chapter outlines the work carried out for the shear piezoelectricity of biopolymers as well as optically active polymers. 

Piezoelectricity, pyroelectricity, and ferroelectricity is hardly confined to synthetic polymers. Some biopolymers also possess these properties, and scientists study them to understand how nature exploits these properties. The earliest studies of biopolymer piezoelectricity, for example, go back to 1960s when Morris Shamos and Leroy Lavine (with Michael Morris) studied bone piezoelectricity [39] and later postulated piezoelectricity as a fundamental property of tissues of biological origins [40], In 1968, RNA ferroelectricity was demonstrated by Stanford and Lorey [41]. However, the scientific interest in these properties of biological molecules was dwarfed by the interest in other materials. In 1999 Sidney Lang [42] indicated that compared to thousands of publications on piezoelectric, pyroelectric, and ferroelectric materials, only less than 100 of them were biologically related. 

X H. Maeda and E Pukada, Effect of water on piezoelectric, dielectric, and elastic properties of bone. Biopolymers 21 2055 (1982). 

Microorganisms that are efficient in producing AMV are cellular factories for this 5-carbon monomer, which is a polyamide building block. The AMV monomer is a precursor of valero-lactam, which is important for nylon-5 homopolymer synthesis. This would drive the biopolyamide and biopolymer fields. The polymers, nylon-4,5 and nylon-5,5, can be produced by the polymerization of glutarate with putrescine and cadaverine, respectively. These polymers have additional piezoelectric and ferroelectric properties that are useful in sensors and electronics. 

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