Video microscopy of NCAP films: the observation of LC droplets in real time

Robert H. Reamey; Wayne Montoya; Abraham Wong

doi:10.1117/12.60371

15 June 1992 Video-microscopy of NCAP films: the observation of LC droplets in real time

Robert H. Reamey, Wayne Montoya, Abraham Wong

Proceedings Volume 1665, Liquid Crystal Materials, Devices, and Applications; (1992) https://doi.org/10.1117/12.60371
Event: SPIE/IS&T 1992 Symposium on Electronic Imaging: Science and Technology, 1992, San Jose, CA, United States

Abstract

We have used video-microscopy to observe the behavior of liquid crystal (LC) droplets within nematic droplet-polymer films (NCAP) as the droplets respond to an applied electric field. The textures observed at intermediate fields yielded information about the process of liquid crystal orientation dynamics within droplets. The nematic droplet-polymer films had low LC content (less than 1 percent) to allow the observation of individual droplets in a 2 - 6 micrometers size range. The aqueous emulsification technique was used to prepare the films as it allows the straightforward preparation of low LC content films with a controlled droplet size range. Standard electro-optical (E-O) tests were also performed on the films, allowing us to correlate single droplet behavior with that of the film as a whole. Hysteresis measured in E-O tests was visually confirmed by droplet orientation dynamics; a film which had high hysteresis in E-O tests exhibited distinctly different LC orientations within the droplet when ramped up in voltage than when ramped down in voltage. Ramping the applied voltage to well above saturation resulted in some droplets becoming `stuck'' in a new droplet structure which can be made to revert back to bipolar with high voltage pulses or with heat.

Citation Download Citation

Robert H. Reamey, Wayne Montoya, and Abraham Wong "Video-microscopy of NCAP films: the observation of LC droplets in real time", Proc. SPIE 1665, Liquid Crystal Materials, Devices, and Applications, (15 June 1992); https://doi.org/10.1117/12.60371

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available