Overestimation of Operational Stability in Polymer-Based Organic Field-Effect Transistors Caused by Contact Resistance.

The bias-stress effects of bottom-gate top-contact polymer-based organic field-effect transistors (OFETs) with different channel lengths (50-500 μm) were evaluated by repeating cycles of prolonged on-state gate-bias application and transfer characteristics measurements in the linear regime. The thicknesses of poly(didodecylquaterthiophene--didodecylbithiazole) active layers were 26 and 37 nm. All OFETs exhibited nonlinear (nonideal) transfer characteristics with a maximum transconductance within the gate-source voltage sweep range.

Ionic Liquid Crystal-Polymer Composite Electromechanical Actuators: Design of Two-Dimensional Molecular Assemblies for Efficient Ion Transport and Effect of Electrodes on Actuator Performance.

We present the development of free-standing ionic liquid crystal-polymer composite electrolyte films aimed at achieving high-frequency response electromechanical actuators. Our approach entails designing novel layered ionic liquid-crystalline (LC) assemblies by complexing a mesomorphic dimethylphosphate with either a lithium salt or a room-temperature ionic liquid through the formation of ion-dipole interactions or hydrogen bonds. These electrolytes, exhibiting room-temperature ionic conductivities on the order of 10 S cm and wide LC temperature ranges up to 77 °C, were successfully integrated into porous polymer networks.

Highly luminescent and photoconductive columnar liquid crystals with a thiophene-oxadiazole backbone.

We report columnar liquid-crystalline thiophene-oxadiazole molecules, which can be oriented by electric field and exhibit photodiode properties with an open-circuit voltage of 1 V. Their yellow luminescence can be excited by UV-visible or infrared light. Their room-temperature phosphorescence turns brighter upon heating.

Room-Temperature Zwitterionic Liquid Crystals for Mechanical Actuators.

We have developed room-temperature smectic liquid-crystalline (LC) ion conductors by the self-assembly of a zwitterionic mesogenic compound and a series of fluorinated lithium salts. The conductivity of lithium bis(trifluoromethylsulfonyl)imide LC complex reached 4 × 10 S cm at ambient conditions. This LC complex sandwiched between two conductive polymer electrodes can be used in low-voltage mechanical actuators with a peak-to-peak bending deflection of ca.

Photocured Liquid-Crystalline Polymer Electrolytes with 3D Ion Transport Pathways for Electromechanical Actuators.

Self-assembly of ionic molecules into hierarchical ordered structures is a promising route to new types of solid electrolytes with enhanced ion transport. Herein, we report a liquid-crystalline polymer electrolyte membrane that contains three-dimensionally (3D) interconnected ionic pathways. To build this membrane, we used wedge-shaped amphiphilic molecules that have two ionic heads and a lipophilic tail.