Image credit: American Chemical SocietyFrustrated by a mobile device's inability to hold a charge, researchers designed a child’s smart puzzle using a simple, lightweight and flexible Smart Puzzle Triboelectric Nanogenerator (SP-TENG) to both produce and store energy without having to rely on a battery.

The research team, led by Sang-Jae Kim, originally considered other solutions such as solar cells (as used in calculators), supercapacitors (as used in hybrid car batteries) and small specialized generators. However, the team considered current TENGs to be too complex, rigid and bulky for their design.

Instead, the team used recycled parts to design a TENG that was flexible, lightweight and portable. The TENG puzzle was able to withstand significant periods of operation time without causing much damage to the electrical signal.

The research appears in the journal ACS Sustainable Chemistry and Engineering.