Triboelectric nanogenerator generates electricity with tiny beads

https://www.eurekalert.org/news-releases/1076519

"surface made up of closely packed small beads comes into contact with surface containing same, smaller beads generally gain positive charge, larger negative... most significant effect with melamine-formaldehyde beads (low elasticity)... cost-effective... dry fabrication more sustainable, no solvents... wearables, small devices not needing charging... future: better efficiency/ reliability enabling large-scale applications. materials/ structures research continues to reveal new opportunities for energy generation and use"