# Investigating the Electro-Optic Response of Steroid Doped Liquid Crystal Devices
## 4 Conclusions  
A series of steroidal compounds were tested as chiral dopants for LC systems. One steroid that had yet to be reported as a chiral dopant, progesterone, was found to be miscible with common nematic LC E7 and MLC-2079 at concentrations of 10 wt. %. The use of progesterone as a co-dopant for commercially available R1011 in PSCLCs with red- and blue-tuning behavior was successfully fabricated. Progesterone also functioned as a chiral dopant for normal and reverse mode switchable CLCs and exhibited the desired responsive behavior. To further demonstrate the utilization of different classes of biomolecules, the bile acid lithocholic acid was probed as a potential chiral dopant. Although lithocholic acid is insoluble, simple synthetic modification was able to improve the miscibility in common LCs, as the two derivatives were stable at concentrations of 10 wt. %. Future studies will focus on synthetic modification using targeted side chains to improve the HTP of lithocholic acid derivatives to achieve values on par with high HTP commercially available dopants. Additionally, studies will be conducted to identify new classes of biomolecules that have potential usage as chiral dopants in CLCs and relevant CLC technologies.  
The supporting information can be downloaded at [[https://www.mdpi.com/article/10.3390/app13085054/s1](https://www.mdpi.com/article/10.3390/app13085054/s1)]([https://www.mdpi.com/article/10.3390/app13085054/s1](https://www.mdpi.com/article/10.3390/app13085054/s1)). Figure S1: 1H NMR of LA-Me; Figure S2: 1H NMR of LA-Bn; Figure S3: POM images of (a) \(\delta\)-estradiol, (b) cholesterol, (c) progesterone, (d) LA-Bn, and (e) LA-Me at 10 wt. % in nematic LC E7; Figure S4: Chemical structures of the photoinitiator I-369, chiral dopant R1011, liquid crystal monomer RM82, and the eutectic liquid crystal mixture E7; Figure S5: Reflection notch data for (a) 9.1 wt. % progesterone, (b) 9.3 wt. % LA-Bn, and (c) 10.1 wt. % LA-Me in nematic LC E7; Table S1: Helical twisting power of the bio-chiral dopants used in the responsive CLC samples; Table S2: Formulations for the normal mode (NM), reverse mode (RM), blue tuning (BT), and red-tuning (RT) CLCs and PSCLCs containing progesterone, LA-Bn, and LA-Me.  
Conceptualization, N.P.G., S.M.Q., S.M.W. and Z.M.M.; validation, K.M.L., S.M.W. and Z.M.M.M.; formal analysis, S.M.W., Z.M.M., S.K., K.M.L. and N.P.G.; investigation, S.M.Q., S.K., K.M.L., S.M.W., Z.M.M. and N.P.G.; resources, N.P.G., T.A.G. and M.E.M.; data curation, Z.M.M., S.M.W. and K.M.L.; writing--original draft preparation, S.M.W. and Z.M.M.; writing--review and editing, N.P.G., S.M.W. and Z.M.M.M.; visualization, N.P.G., S.M.W. and Z.M.M.; supervision, N.P.G. and T.A.G.; project administration, N.P.G.; funding acquisition, N.P.G. and T.A.G. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the AFRL Materials and Manufacturing Directorate, Grant Number: FA8650-22-F-5406, and DARPA Living Foundries.  
Data is contained within the article or Supplementary Materials.  
The authors declare no conflict of interest.