Jieke Jiang

Fabrication of Transparent Multilayer Circuits by Inkjet Printing

Conductive microcables embedded in a transparent film are fabricated by inkjet printing silver-nanoparticle ink into a liquid poly(dimethylsiloxane) (PDMS) precursor substrate. By controlling the spreading of the ink droplet and the rheological properties of the liquid substrate, transparent multilayer circuits composed of high-resolution embedded cables are achieved using a commercial inkjet printer. This facile strategy provides a new avenue for inkjet printing of highly integrated and transparent electronics.

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.

Self-Healable Organogel Nanocomposite with Angle-Independent Structural Colors

Structural colors have profound implications in the fields of pigments, displays and sensors, but none of the current non-iridescent photonic materials can restore their functions after mechanical damage. Herein, we report the first self-healable organogel nanocomposites with angle-independent structural colors. The organogel nanocomposites were prepared through the co-assembly of oleophilic silica nanoparticles, silicone-based supramolecular gels, and carbon black. The organogel system enables amorphous aggregation of silica nanoparticles and the angle-independent structural colors in the nanocomposites. Moreover, the hydrogen bonding in the supramolecular gel provides self-healing ability to the system, and the structural colored films obtained could heal themselves in tens of seconds to restore storage modulus, structural color, and surface slipperiness from mechanical cuts or shear failure repeatedly.

Development of “Liquid-like” Copolymer Nanocoatings for Reactive Oil-Repellent Surface

Here, we describe a simple method to prepare oil-repellent surfaces with inherent reactivity. Liquid-like copolymers with pendant reactive groups are covalently immobilized onto substrates via a sequential layer-by-layer method. The stable and transparent nanocoatings showed oil repellency to a broad range of organic liquids even in the presence of reactive sites. Functional molecules could be covalently immobilized onto the oil-repellent surfaces. Moreover, the liquid repellency can be maintained or finely tailored after post-chemical modification via synergically tailoring the film thickness, selection of capping molecules, and labeling degree of the capping molecules. Oil-repellent surfaces that are capable of post-functionalization would have technical implications in surface coatings, membrane separation, and biomedical and analytical technologies.

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.

Fabrication of Bendable Circuits on a Polydimethylsiloxane (PDMS) Surface by Inkjet Printing Semi-Wrapped Structures

In this work, an effective method was developed to fabricate bendable circuits on a polydimethylsiloxane (PDMS) surface by inkjet printing semi-wrapped structures. It is demonstrated that the precured PDMS liquid film could influence the depositing morphology of coalesced silver precursor inkjet droplets. Accordingly, continuous and uniform lines with a semi-wrapped structure were fabricated on the PDMS surface. When the printed silver precursor was reduced to Ag nanoparticles, the fabricated conductive film exhibited good transparency and high bendability. This work presented a facile way to fabricate flexible patterns on a PDMS surface without any complicated modification or special equipment. Meanwhile, an in situ hydrazine reduction of Ag has been reported using the vapor phase method in the fabricating process.

Development of multifunctional liquid-infused materials by printing assisted functionalization on porous nanocomposites

We report stable and mechanically robust bi-component nanocomposites capable of post modification for the development of multifunctional liquid-infused materials. The non-polar polymer network provides mechanical robustness and compatibility to mineral oils for lubrication and surface slipperiness, and the polar nanoparticles improve the loading capacity of polar molecules for functionalization. Besides the surface slipperiness, we successfully integrate desirable physicochemical properties into nanocomposites by printing specific inks on the nanocomposites. Unique properties including controlled surface slipperiness, self-reporting on the loss of liquid repellency, and sensing the temperature of contacting liquids are demonstrated on the printed nanocomposites with lubrication treatment. Our design strategy could be applied in the development of multifunctional liquid-infused materials for applications in anti-fouling coating, food/medical packaging, smart windows and sensors.

Inkjet Printing: Fabrication of Transparent Multilayer Circuits by Inkjet Printing (Adv. Mater. 7/2016)

By inkjet-printing silver-nanoparticle ink into a liquid substrate, Y. Song and co-workers fabricate conductive microcables that are embedded in a transparent film, in work described on page 1420. By controlling the spreading of the ink droplet and the rheological properties of the liquid substrate, transparent multilayer circuits composed of high-resolution embedded cables are achieved using a commercial inkjet printer. As the silver cables are encapsulated by a poly(dimethylsiloxane) (PDMS) matrix, the embedded circuits can bend reversibly without an apparent resistance increase. This facile strategy provides a new avenue for inkjet-printing of highly integrated and transparent electronics, which is highly desirable in wearable electronics and implantable devices.