Interactions at heterointerfaces influence actuation in wet cast 1T-MoS₂ and V₂O₅ ⋅ 0.5 H₂O thin films

Baker, J. B.; Murphy, K. P.; Aubrey, M. L.

J. Mat. Chem. A 2025, 10.1039/D5TA02659H.

• SI & Media:

Interfacial interaction strengths are often invoked as determining factors in the chemomechanical coupling across actuating lamellar structures. However, electrochemical layered actuators of 100 nanometers to a few microns in thickness are often well described with classical models in which depend only on bulk elastic moduli and relative thicknesses. We report a set of electrochemical systems composed of flexible working electrodes based on sub-micron thin films of 1T-MoS₂ and V₂O₅ · 0.5H₂O deposited onto metallic Au and Ni surfaces. Changes in electrode curvature were measured as a function of applied potential from which induced strains and stresses were calculated using a Timoshenko multi-layer beam bending model. The 1T-MoS₂ system achieved a maximum actuation strain of 0.57(5)% and 1.29(13)% while the V₂O₅ · 0.5H₂O system achieved that of 1.17(8)% and 1.2(2)% on Ni and Au respectively. Based on these results, small differences in interfacial interactions such as in the case of the V₂O₅ · 0.5H₂O were not distinguishable, while for very thin films of 1T-MoS₂ where strong differences between Au–S and Ni–S were present, the strong Au–S interaction resulted in greater actuation strain.