So! Committing to this challenge. 

Let's start with the WHY: well. that's a challenge, and I've got a couple of things I've always wanted to try out:

• Sculpture, easy to assemble
• Couple of touch points
• Contains a MUD of sort
• Thin, because, well.. business case

The WHAT is easy:

• A space where people explore their contact. 
• A nice looking card, electronic sculpture like 
• Possibility to encase it in epoxy

The HOW around a couple of topics:

• Energy: I've thought NFC, Solar, .. but going for another approach definitely ;)
• Heart: ESP32 is relatively stable. There were a couple of NFC chips but I don't have bandwidth to play with them.
• IOs: Visuals: array of leds is tough. A small OLED screen should do the trick. 

Hackaday contraints:

• Wafer thin; let's keep it thin-ish. The usb plug might be the bigger part
• Aesthetics: yeah, definitely
• Cheap: let's go for off the shelf, aliexpress components
• Fun and games: having a toy: definitely if / with a MUD.
• Utilitarian: see the above =)

Rules:

• Form factor: around 90x50mm - fits in a pocket
• Do a bit more than traditional business card: yup
• Documenting: that's what we do.
• Design: won't be much design files, but documenting should do the trick.