Polysiloxane-based liquid crystal block copolymers for piezoelectric and mechano-optical applications

摘要

Liquid crystal research has gained interest in a wide range of applications that go beyond displays. Some of these applications include memory devices, sensors, and variable light valves. Currently, liquid crystals in the form of small molecules are capable of exhibiting fast response times; however, there are many advantages to using block copolymers in these applications, such as the surface stabilization caused by the block copolymer morphology, and recent research has increased in the area of LC block copolymers. In this group, LC block copolymer research has focused on diblock copolymers with one amorphous block and one side-chain LC block, and examined fundamental phase behavior of these complex systems, and the interplay between liquid crystal and block copolymer ordering. This research seeks to examine the potential use of ferroelectric and nematic LC block copolymer elastomers as actuators. These devices can be used as artificial muscles, in microrobotics, in micromachinery, in MEMS, and in other applications that require gates or valves. Artificial muscles have previously been prepared using multilayer composites of conducting polymers and non-conducting materials that may or may not be polymers. Similar functionality could also be accomplished by preparing an amorphous-LC block copolymer with cylindrical morphology. The proposed polymers for this research offer unique processing, mechanical, and electrical advantages over the current technologies because they are both block copolymers and elastomers.