April 21 - April 27

Week 4
During this past week, additional research was done on the properties of PDLC films. Rather than past weeks where the smart glass itself was referenced, the polymer dispersed liquid crystals were researched in order to gain a better understanding of the technology at the nanoscale. Also during this past week, initial steps of the design process were taken when Cadence, a software for designing and simulating custom electrical circuits, was introduced in class. This program will be very useful for simulating different designs for the ambient light dimmer switch. 


Many existing solutions have employed just two settings for the transparency of the PDLC film, on or off. Controlling the voltage using the intensity of ambient light will allow for many slight changes in voltage and multiple settings for the transparency of incoming light. Liquid crystals are widely used as a solution because their orientation is dependent on applied voltage and it is an extremely durable and long-lasting material. The electro-optical properties of polymer dispersed liquid crystal films are altered based on the wavelength of light, applied voltage, the domain size of the liquid crystals, and temperature. 


A manual switch will be included in the circuit in addition to the ambient light dimmer switch in order to allow the user more control over the amount of light in a space. This will give the user more flexibility over the privacy and security provided by the windows. 

[6]. Surface SEM image of polymer dispersed liquid crystal composite.

This image shows the polymer dispersed liquid crystal micro droplets. In this picture, the PDLC micro droplets are scattered in a solid but porous polymer matrix.

April 14 - April 20

Week 3
The main focus of this week was working on the Design Proposal, as this provides an outline for the construction and testing of the prototype. The schedule was planned to ensure that the construction of the project would be complete in order to finalize the design in week 10. The time to complete initial research, the project proposal, material procurement, and the privacy glass design is expected to be finished by the end of week 5. Construction of the prototype, testing, and data analysis should be completed by the end of week 9, in order to finalize the design in week 10. A few different companies were contacted to get an estimate for the budget as well. The goals and deliverables of the project can be found on the Design Proposal page. 

 [4].

Some common applications of privacy glass were also researched this week. Privacy glass is widely used in residences, skylights, offices, and museums, as direct sunlight should not come in contact with the paintings and other pieces of artwork. 

April 9 - April 13

Week 2
Over the course of this week, initial research was conducted on existing companies and the mechanics of polymer dispersed liquid crystal (PDLC) films. During the first group meeting, the Project Personnel page was set up and project responsibilities were assigned. A better understanding of PDLC films and advancements in the field was gained while researching as a group. Companies such as Switchlite, LTI Smart Glass, and SSI Displays all advertise privacy at the flip of a switch, but we wanted to go further by actively controlling the transparency of the PDLC film using a potentiometer. The following video is an example of the advanced technologies in this field.

 [2].

Depiction of the PDLC film within the window pane, showing the orientation of the crystals [4].

By adjusting the transparency of the polymer dispersed liquid crystal film based on the reading from a light sensor, the window would be able to go beyond the two settings of an on and off switch. The amount of voltage applied to the PDLC film would be directly related to the intensity of the incoming light.