| 1. |
- Menétrey, Maxence, et al.
(author)
-
Targeted Additive Micromodulation of Grain Size in Nanocrystalline Copper Nanostructures by Electrohydrodynamic Redox 3D Printing
- 2022
-
In: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 18:51
-
Journal article (peer-reviewed)abstract
- The control of materials’ microstructure is both a necessity and an opportunity for micro/nanometer-scale additive manufacturing technologies. On the one hand, optimization of purity and defect density of printed metals is a prerequisite for their application in microfabrication. On the other hand, the additive approach to materials deposition with highest spatial resolution offers unique opportunities for the fabrication of materials with complex, 3D graded composition or microstructure. As a first step toward both—optimization of properties and site-specific tuning of microstructure—an overview of the wide range of microstructure accessed in pure copper (up to >99.9 at.%) by electrohydrodynamic redox 3D printing is presented, and on-the-fly modulation of grain size in copper with smallest segments ≈400 nm in length is shown. Control of microstructure and materials properties by in situ adjustment of the printing voltage is demonstrated by variation of grain size by one order of magnitude and corresponding compression strength by a factor of two. Based on transmission electron microscopy and atom probe tomography, it is suggested that the small grain size is a direct consequence of intermittent solvent drying at the growth interface at low printing voltages, while larger grains are enabled by the permanent presence of solvent at higher potentials.
|
|
| 2. |
- Moreno-Garcia, D., et al.
(author)
-
A Resonant Graphene NEMS Vibrometer
- 2022
-
In: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 18:28
-
Journal article (peer-reviewed)abstract
- Measuring vibrations is essential to ensuring building structural safety and machine stability. Predictive maintenance is a central internet of things (IoT) application within the new industrial revolution, where sustainability and performance increase over time are going to be paramount. To reduce the footprint and cost of vibration sensors while improving their performance, new sensor concepts are needed. Here, double-layer graphene membranes are utilized with a suspended silicon proof demonstrating their operation as resonant vibration sensors that show outstanding performance for a given footprint and proof mass. The unveiled sensing effect is based on resonant transduction and has important implications for experimental studies involving thin nano and micro mechanical resonators that are excited by an external shaker.
|
|
| 3. |
- Chen, Jianing, et al.
(author)
-
Plasmonic Nickel Nanoantennas
- 2011
-
In: SMALL. - : Wiley. - 1613-6810 .- 1613-6829. ; 7:16, s. 2341-2347
-
Journal article (peer-reviewed)abstract
- The fundamental optical properties of pure nickel nanostructures are studied by far-field extinction spectroscopy and optical near-field microscopy, providing direct experimental evidence of the existence of particle plasmon resonances predicted by theory. Experimental and calculated near-field maps allow for unambiguous identification of dipolar plasmon modes. By comparing calculated near-field and far-field spectra, dramatic shifts are found between the near-field and far-field plasmon resonances, which are much stronger than in gold nanoantennas. Based on a simple damped harmonic oscillator model to describe plasmonic resonances, it is possible to explain these shifts as due to plasmon damping.
|
|
| 4. |
- Pandit, Santosh, 1987, et al.
(author)
-
Precontrolled Alignment of Graphite Nanoplatelets in Polymeric Composites Prevents Bacterial Attachment
- 2020
-
In: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 16:5
-
Journal article (peer-reviewed)abstract
- Graphene coatings composed of vertical spikes are shown to mitigate bacterial attachment. Such coatings present hydrophobic edges of graphene, which penetrate the lipid bilayers causing physical disruption of bacterial cells. However, manufacturing of such surfaces on a scale required for antibacterial applications is currently not feasible. This study explores whether graphite can be used as a cheaper alternative to graphene coatings. To examine this, composites of graphite nanoplatelets (GNP) and low-density polyethylene (LDPE) are extruded in controlled conditions to obtain controlled orientation of GNP flakes within the polymer matrix. Flakes are exposed by etching the surface of GNP–LDPE nanocomposites and antibacterial activity is evaluated. GNP nanoflakes on the extruded samples interact with bacterial cell membranes, physically damaging the cells. Bactericidal activity is observed dependent on orientation and nanoflakes density. Composites with high density of GNP (≥15%) present two key advantages: i) they decrease bacterial viability by a factor of 99.9999%, which is 10 000-fold improvement on the current benchmark, and ii) prevent bacterial colonization, thus drastically reducing the numbers of dead cells on the surface. The latter is a key advantage for longer-term biomedical applications, since these surfaces will not have to be cleaned or replaced for longer periods.
|
|
| 5. |
- Chen, Jun, et al.
(author)
-
Novel Intrinsic Self-Healing Poly-Silicone-Urea with Super-Low Ice Adhesion Strength
- 2022
-
In: Small. - : John Wiley & Sons. - 1613-6810 .- 1613-6829. ; 18:22
-
Journal article (peer-reviewed)abstract
- Accumulation of snow and ice often causes problems and even dangerous situations for both industry and the general population. Passive de-icing technologies, e.g., hydrophobic, liquid-infused bionic surfaces, have attracted more and more attention compared with active de-icing technologies, e.g., electric heating, hot air heating, due to the passive de-icing technology's lower energy consumption and sustainability footprint. Using passive de-icing coatings seems to be one of the most promising solutions. However, the previously reported de-icing coatings suffer from high ice adhesion strength or short service life caused by wear. An intrinsic self-healing material based on poly-silicone-urea is developed in this work to address these problems. The material is prepared by introducing dynamic disulfide bonds into the hard phase of the polymer. Experimental results indicate that this poly-silicone-urea has a self-healing efficiency of close to 99%. More interestingly, it is found that the coating prepared from this poly-silicone-urea has a super low ice adhesion force, only 7 ± 1 kPa, which is almost the lowest value compared with previous intrinsic self-healing de-/anti-icing reports. This material can maintain low ice adhesion strength after healing. This intrinsic self-healing poly-silicone-urea can meet several practical applications, opening the door for future sustainable anti-/de-icing technologies.
|
|
| 6. |
- Köksal, Elif Senem, et al.
(author)
-
Rapid Growth and Fusion of Protocells in Surface-Adhered Membrane Networks
- 2020
-
In: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 16:38
-
Journal article (peer-reviewed)abstract
- Elevated temperatures might have promoted the nucleation, growth, and replication of protocells on the early Earth. Recent reports have shown evidence that moderately high temperatures not only permit protocell assembly at the origin of life, but can have actively supported it. Here, the fast nucleation and growth of vesicular compartments from autonomously formed lipid networks on solid surfaces, induced by a moderate increase in temperature, are shown. Branches of the networks, initially consisting of self-assembled interconnected nanotubes, rapidly swell into microcompartments which can spontaneously encapsulate RNA fragments. The increase in temperature further causes fusion of adjacent network-connected compartments, resulting in the redistribution of the RNA. The experimental observations and the mathematical model indicate that the presence of nanotubular interconnections between protocells facilitates the fusion process.
|
|
| 7. |
|
|
| 8. |
- Zokaei, Sepideh, 1991, et al.
(author)
-
Electrically Conducting Elastomeric Fibers with High Stretchability and Stability
- 2022
-
In: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 18:5
-
Journal article (peer-reviewed)abstract
- Stretchable conducting materials are appealing for the design of unobtrusive wearable electronic devices. Conjugated polymers with oligoethylene glycol side chains are excellent candidate materials owing to their low elastic modulus and good compatibility with polar stretchable polymers. Here, electrically conducting elastomeric blend fibers with high stretchability, wet spun from a blend of a doped polar polythiophene with tetraethylene glycol side chains and a polyurethane are reported. The wet-spinning process is versatile, reproducible, scalable, and produces continuous filaments with a diameter ranging from 30 to 70 µm. The fibers are stretchable up to 480% even after chemical doping with iron(III) p-toluenesulfonate hexahydrate and exhibit an electrical conductivity of up to 7.4 S cm−1, which represents a record combination of properties for conjugated polymer-based fibers. The fibers remain conductive during elongation until fiber fracture and display excellent long-term stability at ambient conditions. Cyclic stretching up to 50% strain for at least 400 strain cycles reveals that the doped fibers exhibit high cyclic stability and retain their electrical conductivity. Finally, a directional strain sensing device, which makes use of the linear increase in resistance of the fibers up to 120% strain is demonstrated.
|
|
| 9. |
- Ao, Xianyu, et al.
(author)
-
Broadband Metallic Absorber on a Non-Planar Substrate
- 2015
-
In: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 11:13, s. 1526-1530
-
Journal article (peer-reviewed)abstract
- Absorbers for visible and near-infrared light are realized by depositing a thin iron layer on arrays of cones which are replicated from a porous template. The replicated conic structure itself is of several micrometers and ineffective at antireflection, but the subsequent deposition of iron on top generates nanometer-size columnar structures, and thus broadband absorption enhancement is achieved.
|
|
| 10. |
- Bally, Marta, 1981, et al.
(author)
-
Liposome and lipid bilayer arrays towards biosensing applications
- 2010
-
In: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 6:22, s. 2481-2497
-
Journal article (peer-reviewed)abstract
- Sensitive and selective biosensors for high-throughput screening are having an increasing impact in modern medical care. The establishment of robust protein biosensing platforms however remains challenging, especially when membrane proteins are involved. Although this type of proteins is of enormous relevance since they are considered in >60% of the pharmaceutical drug targets, their fragile nature (i.e., the requirement to preserve their natural lipid environment to avoid denaturation and loss of function) puts strong additional prerequisites onto a successful biochip. In this review, the leading approaches to create lipid membrane-based arrays towards the creation of membrane protein biosensing platforms are described. Liposomes assembled in micro- and nanoarrays and the successful set-ups containing functional membrane proteins, as well as the use of liposomes in networks, are discussed in the first part. Then, the complementary approaches to create cell-mimicking supported membrane patches on a substrate in an array format will be addressed. Finally, the progress in assembling free-standing (functional) lipid bilayers over nanopore arrays for ion channel sensing will be reported. This review illustrates the rapid pace by which advances are being made towards the creation of a heterogeneous biochip for the high-throughput screening of membrane proteins for diagnostics, drug screening, or drug discovery purposes.
|
|
