Thermo-mechanically responsive crystalline organic cantilever.

We report thermo-mechanically responsive and thermochromic behavior in the single crystalline organic semiconductor butoxyphenyl N-substituted naphthalene diimide (BNDI). We show that initially monoclinic single crystals of BNDI undergo a single-crystal to single-crystal transition to a triclinic phase. This transition accompanies large changes in the crystal packing, a visible decrease in crystal size, reversible thermochromic behavior, and motion including bending, jumping, and splitting. We have shown that by fixing single crystals to a surface, we can harness the energy of the phase transition to create a single crystal cantilever capable of lifting weights with masses nigh two orders of magnitude heavier than the single crystal itself.