In the past few years, ionic liquids (ILs)-based gels (gels contain ILs) have become a research hotspot. ILs-based gels combine the properties of gels with intrinsic ILs properties. According to the existence form and function of the ILs in the gel, the ILs-based gels are divided into three types. One is ILs hydrogels which the PILs, ILs polymerized into poly-ionic liquids, copolymerized with other polymers served as the continuous phase in the gel system. This type of gel can usually absorb water and is an ILs hydrogel. The other is ionic gels that are usually synthesized by high-molecular organic polymers as spatial network structure and ILs as a dispersed phase, which maintained the good performance of ILs. The third one is that the ILs acts as both the continuous phase and the dispersed phase of the gels. In all research fields, the pursuit of new materials aims at functional materials, which enhances specific and efficiency, and ultimately applications. The application of ILs-based gels ranges from energy storage, sensing, electrochemical devices, to antibacterial and gas capture. Different synthesis methods have different performances and applications of ILs-based gels. The purpose of this review is to provide the latest developments on ILs-based gels, perspectives on several applications, and some challenges that need to be aware of in this field.

Microfluid chips integrating with organic electrochemical transistors (OECTs) are useful for manufacturing biosensors with high throughput and large-scale analyses. We report here the utilization of alternating current (AC) electrodeposition to fabricate OECTs in situ on a microfluid chip. With this method, the organic semiconductor (OS) layer with a channel length of 8 μm was readily prepared without requiring the post-bonding process in the conventional construction of microfluidic chips. Poly(3, 4-ethylenedioxythiophene): poly(4-styrenesulfonate)/graphene quantum dots (PEDOT: PSS/GQDs) composites with different morphologies, such as microfilms, nanodendrites and nanowires were electropolymerized. The mass transfer process of the electropolymerization reaction was evidenced to be diffusion limited. Morphologies, growth directions, and chemical structures of OS layers could be tuned by the amplitude and the frequency of the AC voltage. Transfer and output characteristic curves of OECTs were measured on the microfluidic chip. The maximum transconductance, on/off current ratio and threshold voltage measured in the experiment was 1.58 mS, 246, and 0.120 V, respectively.