Thermally Induced Bending of ReS₂ Nanowalls

Among the variety of stimuli-responsive materials, temperature-responsive materials (TRMs) can adapt to the surrounding environment in the presence of a thermal stimulus, and they have attracted considerable attention in sensors, actuators, and surface engineering. However, polymers, as the most representative TRMs, are far from ideal with respect to long-term reliability and durability. Here, for the first time, an inorganic material, ReS₂ , is analyzed, which possesses an unexpected temperature-responsive behavior that is triggered by stable and reversible thermally induced bending (TIB). Due to thermal fluctuations in the ReS₂ layers, intrinsic ripples tend to aggravate rapidly with rising temperature. Then, the weak interlayer interaction of ReS₂ is further weakened, thus resulting in interlayer sliding. Due to a decrease in bending rigidity with increasing temperature, out-of-plane bending spontaneously occurs in the ReS₂ layers. Interestingly, this TIB of ReS₂ can recover to its initial configuration when the temperature drops, which is further confirmed by the reversible wetting measurement. Above all, the TIB behavior of ReS₂ exhibits great potential in smart applications, such as smart windows and microfluidic devices, and fills the significant gaps of inorganic TRMs.