Awesome project. Could you share any details on how you did the antenna? Looks like its in the PCB.

Yes, it's a PCB trace antenna. ST has good documentation on how to draw it so that it matches the required inductance. There's even a edesignsuite tool that helps. I'm a big fan of ST documentation. https://www.st.com/resource/en/application_note/an2972-how-to-design-an-antenna-for-dynamic-nfc-tags-stmicroelectronics.pdf

That is convenient! What a thorough document. Nice to have since I know nothing about antenna design. I am thinking of trying both this, and a basic rectification circuit instead of the ST25. It'd be nice if it could just work with a few caps and diodes. I am not sure I know how to program the ST25 if it comes to that.

hi, this is quite close to a little project I am trying to make, wondering if you could help me 

Ok, we're in 2023, but it's still cool. By the way, I have a business idea, but I am afraid of starting it. Fortunately, I found https://paperap.com/free-papers/business/ that made me think that I could do it. It offered me some information on this topic and I really appreciate the free essays on business I read on this source.

This is really cool. A bit of an overkill, but really cool. 

Really cool project. How much power are you able to harvest with the current design? and is the project open source? I wanted to created something like this but with a twist it will save with the layout.