Superhigh-ε materials that exhibit exceptionally high dielectric permittivity are recognized as potential candidates for a wide range of next-generation photonic and electronic devices. In general, achieving a high-ε state requires low material symmetry, as most known high-ε materials are symmetry-broken crystals. There are few reports on fluidic high-ε dielectrics. Here, we demonstrate how small molecules with high polarity, enabled by rational molecular design and machine learning analyses, enable the development of superhigh-ε fluid materials (dielectric permittivity, ε > 10⁴) with strong second harmonic generation and macroscopic spontaneous polar ordering. The polar structures are confirmed to be identical for all the synthesized materials. Furthermore, adapting this strategy to high–molecular weight systems allows us to generalize this approach to polar polymeric materials, creating polar soft matters with spontaneous symmetry breaking.

Dielectric permittivity, a measure of polarisability, is a fundamental parameter that dominates various physical phenomena and properties of materials. However, it remains a challenge to control the dielectric permittivity of materials reversibly over a large range. Herein, we report an anisotropic fluid with photoresponsive dielectric permittivity (200 < ε < 18,000) consisting of a fluorinated liquid-crystalline molecule (96 wt%) and an azobenzene-tethered phototrigger (4 wt%). The reversible trans-cis isomerisation of the phototrigger under blue and green light irradiation causes a switch between two liquid-crystalline phases that exhibit different dielectric permittivities, with a rapid response time (<30 s) and excellent reversibility (~100 cycles). This anisotropic fluid can be used as a flexible photovariable capacitor that, for example, allows the reversible modulation of the sound frequency over a wide range (100 < f < 8500 Hz) in a remote manner using blue and green wavelengths.

In recent years, ferroelectric nematic liquid crystals have attracted considerable attention owing to their unique properties such as a colossal polarization, high electro-optic activity, and high fluidity. However, despite large efforts in designing and developing new ferrofluid molecules based on molecular parameters, the control and stabilization of ferroelectric nematic phase transitions remain challenging. Here, we discuss the impact of mixing 1,3-dioxane-tethered fluorinated (DIO) diastereomer molecules, namely ^transDIO and ^cisDIO, in controlling the ferroelectric nematic phase transition, using X-ray diffraction to investigate the effect of smectic cybotactic cluster formation. Our results show that the ferroelectric nematic phase transition can be tuned by a smooth exchange of the ferroelectric nematic ^transDIO and non-liquid crystal ^cisDIO components, where the similar dipole and molecular backbone of the two components ensures a consistent macroscopic polarization of the diastereomeric-controlled ferroelectric nematic phase.

Ferroelectric nematic liquid crystals (N_FLCs) are distinguished by their remarkable polarization characteristics and diverse physical phenomena, sparking significant interest and excitement within the scientific community. To date, over 150 N_FLC molecules are developed; however, there are no reports regarding straight linear polar molecules with a parallel alignment of the permanent dipole moment and the molecular axis. The straight polar mesogen nBOE exhibits an enantiotropic N_F phase with a wide temperature window (up to 100 K) despite having a longer alkyl chain (up to n = 6) than the critical alkyl chain length of conventional models. Interestingly, nBOE with a medium‐length alkyl chain displays an exotic phase sequence of N_F–^HCN_F–SmX_F during the elimination of positional displacement among adjacent molecules. Furthermore, the reflective color modulation of the ^HCN_FLC over the entire VIS‐NIR spectral regime by ultralow E‐field (up to 0.14 V µm⁻¹) is demonstrated.