I am new to making PCBs, but i had the idea to make a 2x7 inch flexible pcb bookmark that lights up whenever a book is closed on it… having trouble deciding what switch to use for this but a membrane switch seems like the best bet… i just have no idea how to implement it into the pcb or if it is even possible.

 

My gut feeling says it would not put enough pressure on the switch to be reliable.

 

There are a number of companies that make them but I think the price is above what you can afford.
For a prototype look at this.
Here is a picture. The top layer is just for looks. The two tan colored layers are made using "flexible PCBs".
The red layer is probably also a flex layer, with holds. Just thick enough to hold the copper layers apart.
Bottom layer is sticky.

Hope this gives you some ideas.
JLCPCB is now making clear PCBs and flex PCB and many different kinds. I think you can stack up three or more layers and get something to work.

 

You can purchase dome switches with different activation forces.
It is a simple matter to layout the contacts on a PCB. I tape the switches to the PCB with ordinary "Scotch" tape.

 

Ok it doesn’t seem so cost effective or reliable when book closes…is there any other type of switch or sensor I could look into that may suit it better

 

Ok it doesn’t seem so cost effective or reliable

Don’t take my word for that! I said it was my “gut feeling.” I meant that you should do some research and testing before committing to that type of sensor and making a PCB that might not work.

Suggesting another type of sensor would depend on what you are trying to do with this. Tell us how and why it would be used and we might be able to suggest something else.

 

Audio books for children often use a sliding tab that closes battery connections when the book is opened.