1a_spacer.brd and 2a_Electodes.brd is not same as mentioned in paper.

[AbidHussain70]

No description provided.

[bhclowers]

Hopefully, this will address the issue: https://github.com/bhclowers/OS-IMS/tree/master/PCB_IMS/Revision_Dec2020

[bhclowers]

It looks like you might not have the appropriate layers set on your cam export settings for Eagle. You need to make sure you are exporting your mill and dimension layers appropriately. In the future, please create a separate issue to keep things organized.

Sparkfun and Adafruit have some decent tutorials on how to set this. Also, Eagle has a layer preview setting that can be useful.

https://learn.sparkfun.com/tutorials/designing-pcbs-advanced-smd/gerber-generation

Your board should look something like this:

Good luck!