Earth Runners
US-made barefoot sandals for warm weather, natural movement and grounding: minimal construction, cotton canvas footbed options, flexible zero-drop soles and a strong barefoot philosophy.
Sandal-only harm reduction, not a closed-shoe solution. Outsoles, straps, conductive elements, dyes and adhesives remain caveats. Check current shipping to Europe before you rely on it.
A US source in the The Second Skin directory. Check that it ships to Europe; where it does not, the directory lists a European alternative alongside it.