To impose diffraction-grating patterns on the surface of LCEs, we used an NIL system (Eitre 3, Obducat) to press a sample into a silicon mold, using a pressure of 3 MPa, while exposing them to UV light (300 to 400 nm, 20 mW/cm2) for 1 min. The imprinting process extruded the LCE sample into the mold cavities while simultaneously using UV light to activate bond exchange; the process did not alter the material chemistry. To fix patterns in the LC phase, imprinting was done at 55°C, while a temperature of 99°C was used to program patterns in the isotropic state. To characterize the evolution of patterns during heating and cooling, a custom hot stage was placed into an AFM (Cypher S, Asylum Research) and imaged using the fast force-mapping technique (Nanosensors probe, PPP-SEIH-20). Three-minute equilibration time was allotted before scanning. No evidence of contamination or metal traces from the imprinting process was observed.

Diffraction measurements were taken by mounting the 25-μm-thick programmed sample onto a heating stage (Instec TS102). A HeNe laser (633 nm) was passed through the sample with the diffraction grating facing away from the laser resulting in three visible spots, two diffraction orders at approximately 50° angles, and transmission spot straight on. Two photodiodes (Newport visible sensors with silicon detectors) were placed in front of the transmission and one diffracted spot, and the corresponding intensities were recorded at various temperatures ranging from 30° to 99°C (±1°C). The diffraction efficiency is defined as the ratio of the intensity of the diffracted beam Idiffracted to the intensity of the transmission beam Itransmission. Thus, diffraction efficiency here is defined asEmbedded Image

Note: The content above has been extracted from a research article, so it may not display correctly.

Please log in to submit your questions online.
Your question will be posted on the Bio-101 website. We will send your questions to the authors of this protocol and Bio-protocol community members who are experienced with this method. you will be informed using the email address associated with your Bio-protocol account.

We use cookies on this site to enhance your user experience. By using our website, you are agreeing to allow the storage of cookies on your computer.