BIGFOOT (cell birefringence)
ShalikaSingh - 14:19, Wednesday 25 September 2024 (3760)
Hydrogel measurement with displacement

[Katsuki, Shalika, Marc]

The thickness of the hydrogel is 1.5mm. The measurement is taken with LC voltage from 0.5V - 3 V with 0.25V step and 10avg.

26.7 cm (F=0g)

C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\cell birefringence\hydrogel\Wed, Sep 25, 2024 10-42-00 AM.txt

26.8 cm

C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\cell birefringence\hydrogel\Wed, Sep 25, 2024 11-45-27 AM.txt

26.9 cm

C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\cell birefringence\hydrogel\Wed, Sep 25, 2024 11-48-42 AM.txt

27 cm

C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\cell birefringence\hydrogel\Wed, Sep 25, 2024 11-52-24 AM.txt

27.1 cm

C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\cell birefringence\hydrogel\Wed, Sep 25, 2024 11-56-57 AM.txt

27.2 cm

C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\cell birefringence\hydrogel\Wed, Sep 25, 2024 12-01-33 PM.txt

27.3 cm

C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\cell birefringence\hydrogel\Wed, Sep 25, 2024 12-06-09 PM.txt

Hydrogel changed here.

27.4 cm (discarded for analysis)

C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\cell birefringence\hydrogel\Wed, Sep 25, 2024 1-46-34 PM.txt

27.5 cm (discarded for analysis)

C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\cell birefringence\hydrogel\Wed, Sep 25, 2024 1-52-02 PM.txt

Comments related to this report
ShalikaSingh - 18:38, Wednesday 25 September 2024 (3761)

The retardation of the data was evaluated and plotted. We can see a linear dependency of retardation(effective and linear retardation) with the stretch of hydrogel. On the other hand, circular retardation and linear retardation along 45deg axis doesn't change.

The distibution of retardation was fit with gaussian fit and the mean and std was estimated. Then for each displacement the analysis was repeated to make the plot 1.

Plot 1 Retardation vs. Displacement

ShalikaSingh - 18:42, Wednesday 25 September 2024 (3762)

The force constant k was evaluated as follows:

mg = kx

k = (delta mg) / (delta x) = ((0.06-0.03) * 9.8)/(0.01 * (28-27))  = 29.4

ShalikaSingh - 08:13, Monday 07 October 2024 (3770)

The diattenuation vs. Displacement is as in Fig 1. Doesn't change with increasing displacement.