Electronic skins, as the integration of multiple distinct sensors, have aroused broad interests owing to their great potential in sensing applications. However, problems including the interference between sensing components and the difficulty in synchronous monitoring are practically encountered when they are applied to mixed signals. In this work, efforts are devoted to trouble‐free technical strategies for laminating three sensors with different sensing abilities into a skin‐like electronic device. The use of ionic liquid, combined with particular circuit topologies, ensures the reliable stability against mechanical disturbance during the real‐time sensing tests. The intrinsic layered structure and three independent sensing functions of natural skins are successfully presented by this particular device in which three sensors with the ease of preparation are spatially integrated. The changes of temperature, pressure, and infrared light can be recorded simultaneously yet without mutual signal interference. The perfect integration of multiple functional sensors into a single skin‐like device without any signal interference makes an important progress for pursuing the goal of future electronic skins that can practically be used as skin.

Early fire alarming is of vital importance to lower the damages led by forest fires. Thus far, methods to monitor the forest fires at their early stage are mainly focused on artificial ground patrol, unmanned aerial vehicle cruise monitoring, observation by watchtower, or satellite inspection, whereas these methods are practically encountered with the problems of untimely feedback before the forest fires are out of control. This work proposes a particular kind of self-powered, low-cost, and green thermoelectric paper chips based on the principle of self-assembly and disassembly of ionic liquids on the surface of gold electrodes. By adjustment of the species of ionic liquids, both "nand p-type" thermoelectric behaviors have been exploited that correspond to the opposite open-circuit voltages. Owing to the fluidic nature of ionic liquids, those "nand p-type" thermoelectric units can be readily connected in series on one paper chip, leading to remarkable voltage signals in the presence of the temperature difference of 35 K. Followed by signal acquisition and transmission, such a thermoelectric paper chip successfully affords immediate electrical alarming at the early stage of an afire circumstance.

electrode surface. The mechanism of thermal harvesting is similar with thermal charge of ionic solution, which is confirmed by previous researches on non-redox ionic thermally capacitive cells. [26,27] It is of importance that Seebeck coefficient (S), power factor (PF), and thermoelectric figure of merit (ZT) are three important parameters used to evaluate the thermoelectric performance of potential thermoelectric materials. To maximize the thermoelectric performance, lower thermal conductivity ( ) κ , higher electrical conductivity (σ), and S are needed according to Equation (1)Herein, we designed a flexible and self-healing thermoelectric converter based on thermosensitive liquids with low temperature gradient. Ionic liquid acting as a thermosensitive fluid was employed owing to their intrinsic merits of liquid materials. The converter generates thermoelectric potential variation of tens of millivolt under low temperature gradient on account of asymmetrically heating. Notably, ionic liquids could also be integrated with flexible substrates or functional nanoparticles to render thermoelectric converter possessing the performance of flexibility, self-healing property, and photo-thermo-electric (PTE) conversion.Four imidazolium cations with different alkyl side chain and two anions including inorganic and organic species were combined to investigate thermoelectric performances of seven ionic liquids, excluding 1-ethyl-3-methyl imidazolium hexafluorophosphate ([EMIm][PF 6 ]) behaving as solid at room temperature. A measurement setup for monitoring the realtime change of open-circuit potential of ionic liquid thermoelectric converter (ILTE converter) was constructed to evaluate the S as shown in Figure 1a,b. The ILTE converter placed on two Peltier devices was heated at left end and kept the other end unheated at room temperature (25 °C). Temperature gradient between two ends of ILTE converter was well maintained owing to poor thermal conductivity of ionic liquid, confirmed by the measured thermal conductivity and thermal imaging of infrared camera (Table 1, Figure S8 and Movie S1, Supporting Information). Typical ILTE converter filled with [EMIm][Tf 2 N] was tested for potential variation generated from alternate heating and cooling of Peltier device (Figure 1c). The potential of left electrode immediately decreases when heated left end of converter. Clearly, this phenomenon results from the different ionic mobility, and cation-anion, ion-metal interactions. With unchanged ionic arrangement on right unheated electrode, ionic rearrangement, and migration on heated end lead to the change of open-circuit potential. The potential variation of converter as the value of 42.2 mV shows the approximately same value under fixed temperature gradient of 26.3 K for six cycles, Concerns of urgent global issues on energy crisis and sustainable development have pushed researchers to find new energy sources and novel strategies to utilize the waste energy in the ambient surroundings. Thermoelectric materials are a kind of promising...

With the use of an ionic liquid as the ultrathermosensitive fluid, a paper thermometer is successfully developed with intrinsic ability of ultrafast response and high stability upon temperature change. The fluidic nature allows the ionic liquid to be easily deposited on paper by pen writing or inkjet printing, affording great promise for large-scale fabrication of low-cost paper sensors. Owing to the advantages of nonvolatilization, excellent continuity and deformability, the thermosensitive ink trapped within the cellulose fibers of paper matrix has no leakage or evaporation at open states, ensuring the excellent stability and repeatability of thermal sensing against arbitrary bending and folding operation. By shortening the heat exchange distance between ionic liquid and samples, it takes only 8 s for the thermometer to reach an electrical equilibrium at a given temperature. Moreover, the paper thermometer can be applied to remotely monitor temperature change with the combination of a wireless communication technology.

Liquid sensors composed of ionic liquids are rising as alternatives to solid semiconductors for flexible and self-healing electronics. However, the fluidic nature may give rise to leakage problems in cases of accidental damages. Here, we proposed a liquid sensor based on a binary ionic liquid system, in which a flowing ionic liquid [OMIm]PF6 is confined by another azobenzene-containing ionic liquid crystalline [OMIm]AzoO. Those crystal components provide sufficient pinning capillary force to immobilize fluidic components, leading to a freestanding liquid-like product without the possibility of leakage. In addition to owning ultra-high temperature sensitivity, crystal-confined ionic liquids also combine the performances of both liquid and solid so that it can be stretched, bent, self-healed, and remolded. With respect to the reconfigurable property, this particular class of ionic liquids is exploited as dynamic circuits which can be spatially reorganized or automatically repaired.

Generation of uniform emulsion droplets mixed with multiple components is one of the key issues in the field of lab in a drop. Traditionally, droplet microfluidic chips are often served as the prime choice while designing and fabricating microfluidic chips always rely on skilled technician and specialized equipment, severely restricting its wide accessibility. In this work, an alternative technique, called multichannel dynamic interfacial printing (MC-DIP), was proposed for multicomponent droplet generation. The MC-DIP device was designed modularly and could be set up manually without any microfabrication process, exhibiting full accessibility for freshmen after a brief training. This new technique owns advantages in the generation of droplets with predictable sizes and composites. Quantitative experiments of measuring minimum inhibitory concentration (MIC) value via mixing microbes and antibiotics into droplet were conducted to proving its application potential for lab in a drop. Further research on a clinical pathogenic strain revealed that this technique could be potentially applied in the clinical laboratory for antibiotic susceptibility testing.

Despite great progresses in bioprinting materials and technologies, immense challenges still remain when printing tubular tissues or organs with satisfying mechanical and chemical properties, such as blood vessel, colon, and trachea. Herein, a promising extrusion system based on an interfacial diffusion printing (IDP) technique for one-step printing of tubular tissue grafts is proposed. Specifically, this technique offers great convenience to prepare hollow hydrogel fibers with excellent mechanical properties and satisfactory biocompatibility. The tubular diameter can be readily adjusted within 6 mm, which renders the possibility of these hydrogel tubes to serve as small-diameter vascular grafts. In the model of animal trials, the hydrogel grafts with the capability of enduring arterial pressure are mechanically stable in rabbit carotid artery replacement. Because of its intrinsic simplicity and generality, the IDP technique is considered to be one of the reliable choices for more complicated bioengineering.

An intrinsically conductive supramolecular polymer is prepared with remarkable thermal sensing and recyclable ability, providing a profound potential in green electronics.