Xingye Zhang

Controlled Inkjetting of a Conductive Pattern of Silver Nanoparticles Based on the Coffee‐Ring Effect

Conductive patterns with line widths of 5-10 µm are successfully fabricated by utilizing the coffee-ring effect in inkjet printing, resulting in transmittance values of up to 91.2% in the visible to near-infrared region. This non-lithographic approach broadens the range of fabrication procedures that can be used to create various nanoparticle-based microstructures and electronic devices.

Fabrication of large-area patterned photonic crystals by ink-jet printing

Large-area patterned photonic crystals (PCs) with multi-stopbands were facilely fabricated by common ink-jet printers using polymer latex suspensions as inks.

Synthesis of monodisperse silver nanoparticles for ink-jet printed flexible electronics.

In this study, monodisperse silver nanoparticles were synthesized with a new reduction system consisting of adipoyl hydrazide and dextrose at ambient temperature. By this facile and rapid approach, high concentration monodisperse silver nanoparticles were obtained on a large scale at low protectant/AgNO(3) mass ratio which was highly beneficial to low cost and high conductivity. Based on the synthesized monodisperse silver nanoparticles, conductive inks were prepared with water, ethanol and ethylene glycol as solvents, and were expected to be more environmentally friendly. A series of electrocircuits were fabricated by ink-jet printing silver nanoparticle ink on paper substrate with a commercial printer, and they had low resistivity in the range of 9.18 × 10( - 8)-8.76 × 10( - 8) Ω m after thermal treatment at 160 °C for 30 min, which was about five times that of bulk silver (1.586 × 10( - 8) Ω m). Moreover, a radio frequency identification (RFID) antenna was fabricated by ink-jet printing, and 6 m wireless identification was realized after an Alien higgs-3 chip was mounted on the printed antenna by the flip-chip method. These flexible electrocircuits produced by ink-jet printing would have enormous potential for low cost electrodes and sensor devices.

A General Strategy for Assembling Nanoparticles in One Dimension

Alignment of 1D assemblies of a wide variety of nanoparticles (e.g., metal, metal oxide, semiconductor quantum dots, or organic microspheres) in one direction upon diverse substrates (including industrial silicon wafers and transparent glass plates) by a general strategy is demonstrated. This sandwich method provides an efficient way of rapidly and precisely assembling nanoparticles on a large scale (up to 10 cm × 10 cm) for device applications.

Nanoparticle Based Curve Arrays for Multirecognition Flexible Electronics.

Assembly of nanoparticles into controllable micro or nanocurve circuits by a feasible strategy is demonstrated. The curves, with various tortuosity morphologies, have tunable resistive strain sensitivity, which can be integrated into a multi-analysis flexible sensor. The curve-based sensor can run complicated facial expression recognition, and may contribute practical applications on auxiliary apparatus for skin micromotion manipulation for paraplegics.

Inkjet-printed highly conductive transparent patterns with water based Ag-doped graphene

Inkjet-printing-based fabrication has been a promising approach with the rapid development and deployment of new material inks. Previous studies have demonstrated inkjet printing of reduced graphene oxide (rGO) or pristine graphene flakes produced by the liquid phase exfoliation method for various devices. Nevertheless, it is still a challenge to inkjet-print conductive patterns with a metal and graphene-based hybrid ink, and to explore the structure effect of metal nanoparticles on the conductivity of graphene-based transparent patterns. Herein, we present a holistic approach to achieve high-performance printed Ag nanotriangle platelet–rGO (Ag NTP–rGO) and Ag polyhedral nanoparticle–rGO (Ag NP–rGO) patterns that addresses the entire process starting from graphene oxide exfoliation, ink formation, printing, to final reduction. Central to this approach is that the solvent of inks is only water, monodisperse Ag nanotriangle platelets (Ag NTPs) and Ag polyhedral nanoparticles (Ag NPs) can be self-assembled on GO which is also used as a dispersant and a stabilizer, and after reduction, compared with rGO, Ag NP–rGO and other rGO-based materials previously reported, the Ag NTP–rGO pattern displays a low sheet resistance of 170 Ω □−1 with a transmittance of 90.2%. This inkjet-printed and reduction process can be broadened to obtain other metal–graphene patterns and devices.

Patterning Fluorescent Quantum Dot Nanocomposites by Reactive Inkjet Printing

Fluorescent quantum dot nanocomposites, including polymer and photonic crystal quantum dots, have been fabricated by reactive inkjet printing. This reactive inkjet printing method has the potential to be broadened to fabrication of other functional nanomaterials, which will find promising applications in optoelectronic devices.

Flexible Circuits and Soft Actuators by Printing Assembly of Graphene

An effective way to improve the electrical conductivity of printed graphene patterns was demonstrated by realizing the assembly of giant graphene oxide sheets during the printing process. The synergetic effect of printing-induced orientation and evaporation-induced interfacial assembly facilitated the formation of laminar-structured patterns. The resulting patterns after chemical reduction showed excellent electrical conductivity in printed graphene electronics. Because of their high conductivity, mechanical flexibility, and advantage in pattern design, printed graphene electrodes were applied in electrical-driven soft actuators, which can realize controllable deformation with low driving voltage. Such achievements will be of great significance for the development of graphene-based flexible and printed electronics.

Facile fabrication of a superhydrophilic–superhydrophobic patterned surface by inkjet printing a sacrificial layer on a superhydrophilic surface

Based on the high wettability contrast, superhydrophilic–superhydrophobic patterned surfaces (SSPSs) have been used in a wide variety of applications, such as cell patterning, droplet transport and analyte enrichment. However, the fabricating approaches of SSPSs are commonly complicated and high-cost. Herein, a facile method was developed to fabricate SSPSs by inkjet printing a sacrificial layer on a superhydrophilic surface. The influence of a pinned three phase contact line on the depositing morphology of the inkjet droplet was investigated, and a uniform structure with high resolution was inkjet printed on the superhydrophilic substrate. Moreover, the patterns of the lines and films were directly inkjet printed on the superhydrophilic surface by regulating the inkjet droplets coalescence. After modifying the surface by fluoro-alkyl silanes and removing the printed water-soluble deposit, the fabricated surface showed high wettability contrast between the printed area and unprinted area. Finally, the fabricated SSPSs were applied to achieve nanoparticle adhesion and droplet transport.

Synthesis, crystal structure, and polymerization of butterfly-shaped thieno[3,2-b]thiophene oligomers

A series of new butterfly-shaped thieno[3,2-b]thiophene oligomers with phenyl and thiophene units were synthesized through Suzuki coupling and Stille coupling reactions. The optical and thermal properties of these materials can be tuned by varying both substituents and the conjugation length. The crystal structures have been determined and showed a syn- or anticlinal conformation in the crystal of molecule 4. The electronic properties of the monomers and their electropolymerization ability are discussed and rationalized as a function of their molecular structure. Moreover, stable cross-linked conjugated polymers were formed by electropolymerization.