Quick search Find article
Quick search
Find article

A microstructure for the detection of vapor-phase analytes based on orientational transitions of liquid crystals

FREE ARTICLE

S S Sridharamurthy1,3,4, K D Cadwell2,3,5, N L Abbott2,6 and H Jiang1,7

Show affiliations


BRIEF COMMUNICATION

We report on the implementation of a microstructure comprising an array of micropillars to create a thin and stable film of nematic liquid crystal (LC), 5CB: 4'-pentyl-4-cyanobiphenyl, and the use of the microsystem for the colorimetric detection of vapor analytes. The microstructure uses capillary force generated by an array of cylindrical micropillars to steadily support a 22 µm thin film of LC, and overcomes susceptibility to gravity and shock. The feasibility of using the microsystem for gas phase detection is demonstrated by using dimethyl methylphosphonate (DMMP) gas to change the orientation of the LC and hence modulate the intensity of light transmitted through a crossed pair of polarizing films. The microstructure potentially offers a simple and portable solution to toxic gas detection.


PACS

61.30.Gd Orientational order of liquid crystals; electric and magnetic field effects on order

68.15.+e Liquid thin films

61.30.Eb Experimental determinations of smectic, nematic, cholesteric, and other structures

07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing

Subjects

Soft matter, liquids and polymers

Instrumentation and measurement

Surfaces, interfaces and thin films

Dates

Issue 1 (February 2008)

Received 24 July 2007

Published 27 November 2007



  1. A microstructure for the detection of vapor-phase analytes based on orientational transitions of liquid crystals

    S S Sridharamurthy et al 2008 Smart Mater. Struct. 17 012001

  2. All order ε-expansion of Gauss hypergeometric functions with integer and half/integer values of parameters

    Mikhail Yu. Kalmykov et al JHEP02(2007)040

  3. Multiple (inverse) binomial sums of arbitrary weight and depth and the all-order ε-expansion of generalized hypergeometric functions with one half-integer value of parameter

    Mikhail Yu. Kalmykov et al JHEP10(2007)048

  4. Gauss hypergeometric function: reduction, ε-expansion for integer/half-integer parameters and Feynman diagrams

    Mikhail Yu. Kalmykov JHEP04(2006)056

  5. On the all-order ε-expansion of generalized hypergeometric functions with integer values of parameters

    Mikhail Y. Kalmykov et al JHEP11(2007)009

  6. Mechanical elasticity of vapour–liquid–solid grown GaN nanowires

    Yunxia Chen et al 2007 Nanotechnology 18 135708

  7. Precision System for Motion Path Parameters Measurement of Wheel and Rail Transport

    I A Konyakhin et al 2006 J. Phys.: Conf. Ser. 48 998

  8. Staggered passive micromixers with fractal surface patterning

    Marco Camesasca et al 2006 J. Micromech. Microeng. 16 2298

  9. Streamers in water and other dielectric liquids

    J F Kolb et al 2008 J. Phys. D: Appl. Phys. 41 234007

  10. Improving Photometric Redshifts Using Galaxy Evolution Explorer Observations for the Sloan Digital Sky Survey Stripe 82 and the Next Generation of Optical and Sunyaev-Zeldovich Cluster Surveys

    Michael D. Niemack et al. 2009 ApJ 690 89

Related review articles

What's this?
View review articles related to this research to gain an insight into the key trends in this subject area. Related review articles are selected based on PACS/MSC codes, and are no more than three years old.

  1. Direct and inverted nematic dispersions for soft matter photonics

View by subject




Export








Please login to access our web services, or create an account if you don't yet have one.

You must have cookies enabled in your web browser to be able to login.

Username
Password

Forgotten your password? Get a new one here.