Nicole R. Bieri

Bio: Nicole R. Bieri is an academic researcher from ETH Zurich. The author has contributed to research in topics: Nanoparticle & Colloidal gold. The author has an hindex of 10, co-authored 16 publications receiving 933 citations. Previous affiliations of Nicole R. Bieri include University of California, Berkeley.

Conductor microstructures by laser curing of printed gold nanoparticle ink

Abstract: The laser-based curing of printed nanoparticle ink to create microlines (resistors) of electrical resistivity approaching that of bulk gold was investigated. The present work relies on laser absorption in both the nanoparticle ink and the sintered gold layer, as well as the transport of thermal energy in the substrate and the resulting solvent vaporization and nanoparticle deposition and sintering. The morphology and electrical properties of the gold line can be controlled by modulating the spatial distribution of the laser beam intensity. Based on the understanding of the underlying physics, a process that circumvents a serious drawback on the functionality of cured gold microlines is produced. Microconductors with resistivity approaching that of bulk gold are produced, while loss of gold nanoparticles and cross sectional nonuniformities are avoided.

Microstructuring by printing and laser curing of nanoparticle solutions

Abstract: In this letter, the process of printing and laser curing of nanoparticle solutions is presented A liquid solvent is employed as the carrier of gold nanoparticles (the material of interest in this study) possessing a low melting temperature compared to that of bulk gold Using a specifically designed printing system, the gold nanoparticle solution is deposited on a substrate and cured with laser radiation In this manner, the potential of writing gold structures on temperature sensitive substrates is demonstrated The interaction between the laser radiation and nanoparticles drives the solvent evaporation and controls the quality of the microstructures printing process The latter is also affected by thermocapillary flow at the free surface, developing during the curing process An optical method for estimating the curing times is also developed and discussed

In-tandem deposition and sintering of printed gold nanoparticle inks induced by continuous Gaussian laser irradiation

Abstract: By employing continuous Gaussian laser irradiation in tandem with a specifically designed drop-on-demand jetting system, nanoparticle inks were printed and sintered on glass substrate A toluene solvent is employed as the carrier of gold nanoparticles possessing a lower melting temperature than that of bulk gold Marangoni flow due to radial surface tension gradient combined with a moving substrate displaces nanoparticle ink in front of and around the laser spot Experiments were carried out changing incident laser power, focused beam waist, and translation speed, and resulting phenomena at different conditions were explained Strong coalescence occurred from 9000–14000 W/cm2, and a gold line with 8 μm of width was demonstrated

Damage-free low temperature pulsed laser printing of gold nanoinks on polymers

Abstract: In this study, pulsed laser based curing of a printed nanoink (nanoparticle ink) combined with moderate and controlled substrate heating was investigated to create microconductors at low enough temperatures appropriate for polymeric substrates. The present work relies on (1) the melting temperature depression of nanoparticles smaller than a critical size, (2) DOD (drop on demand) jettability of nanoparticle ink, and (3) control of the heat affected zone induced by pulsed laser heating. In the experiments, gold nanoparticles of 3–7 nmdiameter dissolved in toluene solvent were used as ink. This nanoink was printed on a polymeric substrate that was heated to evaporate the solvent during or after printing. The overall morphology of the gold microline was determined by the printing process and controlled by changing the substrate temperature during jetting. In addition, the printed line width of about 140 m at the room temperature decreased to 70– 80 m when the substrate is heated at 90° C. By employing a microsecond pulsed laser, the nanoparticles were melted and coalesced at low temperature to form a conductive microline which had just 3–4 times higher resistivity than the bulk value without damaging the temperature sensitive polymeric substrate. This gold film also survived after Scotch tape test. These are remarkable results, considering the fact that the melting temperature of bulk gold is 1064° C and the polymeric substrate can be thermally damaged at temperatures as low as 500° C. DOI: 10.1115/1.1924627

Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology.

Abstract: Although gold is the subject of one of the most ancient themes of investigation in science, its renaissance now leads to an exponentially increasing number of publications, especially in the context of emerging nanoscience and nanotechnology with nanoparticles and self-assembled monolayers (SAMs). We will limit the present review to gold nanoparticles (AuNPs), also called gold colloids. AuNPs are the most stable metal nanoparticles, and they present fascinating aspects such as their assembly of multiple types involving materials science, the behavior of the individual particles, size-related electronic, magnetic and optical properties (quantum size effect), and their applications to catalysis and biology. Their promises are in these fields as well as in the bottom-up approach of nanotechnology, and they will be key materials and building block in the 21st century. Whereas the extraction of gold started in the 5th millennium B.C. near Varna (Bulgaria) and reached 10 tons per year in Egypt around 1200-1300 B.C. when the marvelous statue of Touthankamon was constructed, it is probable that “soluble” gold appeared around the 5th or 4th century B.C. in Egypt and China. In antiquity, materials were used in an ecological sense for both aesthetic and curative purposes. Colloidal gold was used to make ruby glass 293 Chem. Rev. 2004, 104, 293−346

Fundamentals and Catalytic Applications of CeO2-Based Materials

Abstract: Cerium dioxide (CeO2, ceria) is becoming an ubiquitous constituent in catalytic systems for a variety of applications. 2016 sees the 40th anniversary since ceria was first employed by Ford Motor Company as an oxygen storage component in car converters, to become in the years since its inception an irreplaceable component in three-way catalysts (TWCs). Apart from this well-established use, ceria is looming as a catalyst component for a wide range of catalytic applications. For some of these, such as fuel cells, CeO2-based materials have almost reached the market stage, while for some other catalytic reactions, such as reforming processes, photocatalysis, water-gas shift reaction, thermochemical water splitting, and organic reactions, ceria is emerging as a unique material, holding great promise for future market breakthroughs. While much knowledge about the fundamental characteristics of CeO2-based materials has already been acquired, new characterization techniques and powerful theoretical methods are dee...

Evaluation of 3D printing and its potential impact on biotechnology and the chemical sciences.

Abstract: Nearing 30 years since its introduction, 3D printing technology is set to revolutionize research and teaching laboratories. This feature encompasses the history of 3D printing, reviews various printing methods, and presents current applications. The authors offer an appraisal of the future direction and impact this technology will have on laboratory settings as 3D printers become more accessible.

Inkjet printing as a deposition and patterning tool for polymers and inorganic particles

Abstract: Inkjet printing is an attractive patterning technology, which has become increasingly accepted for a variety of industrial and scientific applications. This review primarily presents an overview of the investigations that have been conducted since 2003 into inkjet-printing polymers or metal-containing inks and mentions related activities. The first section discusses the droplet-formation process in piezoelectric drop-on-demand printheads and the physical properties that affect droplet formation and the resolution of inkjet-printed features. The second section deals with the issues that arise from printing polymers, such as printability and the output characteristics of devices made by this route. Finally, the challenges and achievements attached to inkjet printing metal-containing inks are discussed before concluding with a few remarks about the future of the field.

All-inkjet-printed flexible electronics fabrication on a polymer substrate by low-temperature high-resolution selective laser sintering of metal nanoparticles

Abstract: All-printed electronics is the key technology to ultra-low-cost, large-area electronics. As a critical step in this direction, we demonstrate that laser sintering of inkjet-printed metal nanoparticles enables low-temperature metal deposition as well as high-resolution patterning to overcome the resolution limitation of the current inkjet direct writing processes. To demonstrate this process combined with the implementation of air-stable carboxylate-functionalized polythiophenes, high-resolution organic transistors were fabricated in ambient pressure and room temperature without utilizing any photolithographic steps or requiring a vacuum deposition process. Local thermal control of the laser sintering process could minimize the heat-affected zone and the thermal damage to the substrate and further enhance the resolution of the process. This local nanoparticle deposition and energy coupling enable an environmentally friendly and cost-effective process as well as a low-temperature manufacturing sequence to realize large-area, flexible electronics on polymer substrates.