1961

Flexoelectricity

• Kirill Tolpygo developed
• a quantum-mechanical theory
• of optical and elastic
• properties of crystals.
• Crystals in a lattice
• deform under stress.
• Kirill Tolpygo predicted
• when they bend nonuniformly
• then they generate
• an electric field.

Crystal terms

• Shells of ions in a dielectric crystal lattice can bend.
• Ionic crystals, homopolar crystals, cryocrystals, molecular crystals.
• Deformations can introduce Coulomb interactions.

Stored energy

• A long rubber band powers my balsa glider.
• I wind it until the band knots front to back.
• Released, the glider soars through invisible air.
• I am released from earth like a bird.
• Its balsa, plastic propeller, and metal hooks
• maintain static integrity until they hit the barn.
• Everything’s dynamic, bending in space and time,
• undergoing stresses while electrons are careening.