ABSTRACT

　Real-time visualization of the flexion and extension status in joints of athletes is of prime importance for improving their performance and skill. Furthermore, when the injured athletes or elderly person carry out rehabilitation, the visualization of joint flexion status by color changes would motivate them to overcome their injuries and illnesses too.
In this report, we designed and synthesized the cellulose-based liquid crystal materials （hereinafter called “cellulose liquid crystal elastomers”）， which exhibit both reflection colors and lithe elasticity in order to produce the sustainable strainvisualizable sheets. For example, when a cellulose liquid crystalline elastomer film with red reflection was compressed by a transparent plastic spoon, the reflection color in only the compressed area changed from red to yellowish green. Although this yellowish green reflection was maintained as long as the pressure remained constant, the reflection color immediately recovered to the original red by releasing the compressed pressure. This happened from because the elasticity of cellulose liquid crystalline elastomer film. Such pressure-induced color changes of cellulose liquid crystalline elastomer films exhibited the correlation between pressure and reflection color change. Therefore, the reflection color of cellulose liquid crystalline elastomer films allows us to quantitatively visualize the degree of pressure or strain at a glance.

DECENTE SPORTS SCIENCE Vol.46/The DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE