AUXETIC FIDGET – Playful Science - Weird behavior

🌀 AUXETIC FIDGET – Playful Science in the Palm of Your Hand!

This compact little fidget prints fast and brings real mechanical curiosity to your fingertips.

A tactile demo of an unexpected physical behavior—fun, geeky, and oddly satisfying.

🔬 Scientific inspiration
Based on the study by Haver et al. (2024), Elasticity and rheology of auxetic granular metamaterials, published in PNAS
🔗 https://doi.org/10.1073/pnas.2317915121

It reproduces the behavior of an auxetic metagrain.

A grain that contracts in all directions when compressed, thanks to its internal Y-shaped geometry.

🧵 Material required:

→ Must be printed in flexible filament – tested in TPU 95A.
Rigid filaments may break.

🛠️ Two sizes:

• Mini – Ø 14 mm (~12-minute print)
• Big – Ø 23.2 mm (~23/30-minute print)

🎨 Two designs:

1. Simple version
   • Print-in-place
   • No supports — it’s ready straight off the bed
      
2. Full-circle version
   • A sleeker, continuous auxetic ring

   • Requires supports, and they’re not just for show!

     Expect to use some force to break the supports loose — tweezers, pliers, or a firm grip will help. Clean-up is quick once they’re off, but detaching them takes muscle 💪

✨ Why you’ll love it:

• Great feel, strange motion
• Physically demonstrates Poisson’s ratio reversal
• Easy to print, satisfying to squish, and sure to get curious looks