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Search for "PMMA" in Full Text gives 137 result(s) in Beilstein Journal of Nanotechnology.
On the mechanism of piezoresistance in nanocrystalline graphite
Beilstein J. Nanotechnol. 2024, 15, 376–384, doi:10.3762/bjnano.15.34
- measured thickness of the grown film was ca. 5 nm. The NCG film was then transferred onto a 100 μm thick PET substrate. For the transfer process, first, the NCG film on SiO2/Si was coated with 200 nm thick PMMA and put into 5 M NaOH solution at 80 °C. The NCG/PMMA film floats on the surface after the
- etching of SiO2. Using a clean glass wafer, the NCG/PMMA film was transferred from the NaOH solution to a clean water beaker and allowed to float on the top. The cleaning was repeated three times to ensure the no residues of NaOH remained on the NCG film. The film was then removed from the water using a
- PET substrate. After that, the substrate was left in air for drying. Next, a drop of PMMA was dripped on top of the film and allowed to spread and dry. This has been shown to be helpful in removing wrinkles formed during the transfer process [46]. The NCG film on the PET substrate was then patterned
Design, fabrication, and characterization of kinetic-inductive force sensors for scanning probe applications
Beilstein J. Nanotechnol. 2024, 15, 242–255, doi:10.3762/bjnano.15.23
- patterned wafer is ultrasonically cleaned and rinsed with IPA. (c) Back-side mask. Before fabricating the chromium etch mask on the back side, we first protect the wafer’s front side with a thin PMMA layer. We then define the lift-off mask on the wafer back side by spinning a 400 nm thick photoresist
- adhesion of the following 150 nm deposition of chromium with electron-beam evaporation in the Auto306 from Edwards. After the lift-off in mrREM700, we also strip the protective PMMA layer on the front side with AR600–71, and we clean the wafer in isopropanol (IPA). (d) Coarse circuit pattern. A layer of
- with a mask consisting of a 190 nm thick layer of Cr and PMMA. After the release, we strip the PMMA and Cr layers, while taking care to not break the cantilevers. The difficulties associated with using KOH lead us to prefer the dry-etch described above in step (h). Tip deposition In scanning probe
Ion beam processing of DNA origami nanostructures
Beilstein J. Nanotechnol. 2024, 15, 207–214, doi:10.3762/bjnano.15.20
- the direction of the primary ion’s initial momentum. Hillock structures are usually formed upon such interaction with single-crystal materials [19], while craters and particle tracks form on polymeric thin films such as PMMA [20][21]. The dimensions of such features can be influenced by the interplay
- created by the 56Fe10+ ions. In experiments where the surface was fully covered, such as in the work of Thomaz et al. on 2 nm thick PMMA films on Si irradiated with 1.1 GeV Au atoms (∼5.6 MeV/u) [41], the number of incident ions to the number of craters is 1:1. We expect the same behavior in the present
Nanotechnological approaches in the treatment of schistosomiasis: an overview
Beilstein J. Nanotechnol. 2024, 15, 13–25, doi:10.3762/bjnano.15.2
- vivo. Mishra et al. [97] demonstrated similar conclusions using PZQ associated with solid lipid nanoparticles. Malhado et al. [98] concluded that PZQ associated with PMMA nanoparticles could not improve the pharmacokinetic curve. In fact, the absorption of the encapsulated drug was three times lower
TEM sample preparation of lithographically patterned permalloy nanostructures on silicon nitride membranes
Beilstein J. Nanotechnol. 2024, 15, 1–12, doi:10.3762/bjnano.15.1
- using three different fabrication methods: lift-off, ion beam etching (IBE), and stencil lithography. They were further analyzed using different instruments, including scanning electron microscopy, LTEM, and electron holography. A bilayer of positive PMMA resist was utilized in the first fabrication
- advantageous in terms of structural resolution, process simplicity, and the absence of resist residues [21]. We have fabricated ferromagnetic nanodisks on a conventional TEM grid from TedPella® using three different fabrication methods. In the first method, a bilayer of positive PMMA resist yielded an undercut
- mode to avoid melting of the PMMA resist. The second approach involved etching a thin Py film with an ion beam while preserving the intended structure with an electron-beam-patterned negative resist mask. Redeposition of etched material was found to construct fences at the edges of the structures
Recognition mechanisms of hemoglobin particles by monocytes – CD163 may just be one
Beilstein J. Nanotechnol. 2023, 14, 1028–1040, doi:10.3762/bjnano.14.85
- in the uptake of HbMPs. Further research on this topic will be conducted in the future. To be considered as well is a possible mechanism leading to particle uptake by phagocytes based on the particle size. Our own results regarding PMMA-FluoroGreen-COOH particles (microparticles GmbH, Berlin, Germany
- ; N = 3. Different uptake of untagged E. coli (39.8 ± 11.4%) vs HbMP (30′: 51.9 ± 6.0%; 120′: 47.1 ± 5.1%) by monocytes; N = 3. Phagocytosis of PMMA-FluoroGreen-COOH-MP diameter between 0.4 and 2.1 µm by monocytes and granulocytes. N = 3. The confocal laser scanning microscopy image showing the uptake
Optimizing PMMA solutions to suppress contamination in the transfer of CVD graphene for batch production
Beilstein J. Nanotechnol. 2022, 13, 796–806, doi:10.3762/bjnano.13.70
- step that can compromise device performance and reliability, thus hindering industrial production. In this context, the impact of poly(methyl methacrylate) (PMMA), the most common support material for transferring graphene from the Cu substrate to any target surface, can be decisive in obtaining
- reproducible sample batches. Although effective in mechanically supporting graphene during the transfer, PMMA solutions needs to be efficiently designed, deposited, and post-treated to serve their purpose while minimizing potential contaminations. Here, we prepared and tested PMMA solutions with different
- average molecular weight (AMW) and weight concentration in anisole, to be deposited by spin coating. Optical microscopy and Raman spectroscopy showed that the amount of PMMA residues on transferred graphene is proportional to the AMW and concentration in the solvent. At the same time, the mechanical
Fabrication and testing of polymer microneedles for transdermal drug delivery
Beilstein J. Nanotechnol. 2022, 13, 629–640, doi:10.3762/bjnano.13.55
- their biocompatibility, biodegradability, and potential for mass production [12]. Polymers such as polylactic acid (PLA), poly(methyl methacrylate) (PMMA), poly(carbonate), cyclic olefin copolymer (COC) and cycloolefin polymers (COP), polystyrene, and SU-8 photoresists, have all been used for
Electrostatic pull-in application in flexible devices: A review
Beilstein J. Nanotechnol. 2022, 13, 390–403, doi:10.3762/bjnano.13.32
- collapse, the preparation technology is complex. Li et al. [30] prepared cantilever GR-NEM switches with two or three terminals using amorphous silicon as sacrificial layer. Sun et al. [6] prepared a three-terminal switch using PMMA polymer as the sacrifice layer. The graphene beam area was 2.5 µm × 0.5 µm
The effect of metal surface nanomorphology on the output performance of a TENG
Beilstein J. Nanotechnol. 2022, 13, 298–312, doi:10.3762/bjnano.13.25
- . Figure 1 was redrawn from [13] (ϕMetal: metal work function). Electrodeposition process. A PMMA plate was used as the electrodeposition liner. Contact and separation of Cu and PTFE. XRD diffraction patterns of the 16 samples after electrodeposition. Samples 1–8 of the 16 samples were screened and
A comprehensive review on electrospun nanohybrid membranes for wastewater treatment
Beilstein J. Nanotechnol. 2022, 13, 137–159, doi:10.3762/bjnano.13.10
- -workers compared an electrospun PVDF/PMMA MF membrane with a conventionally cast membrane [57]. The electrospun membrane showed higher water permeability and high porosity compared to the cast membrane. Also, the electrospun membrane had a smoother surface, which led to less fouling. Most of the
Assessment of the optical and electrical properties of light-emitting diodes containing carbon-based nanostructures and plasmonic nanoparticles: a review
Beilstein J. Nanotechnol. 2021, 12, 1078–1092, doi:10.3762/bjnano.12.80
- a uniform thin film. Some of the commonly used polymers and metal oxides for ETL are PBD, PBD-PMMA, BND, ZnO, SnO2, and TiO2 [69][70][71]. Improvements in the device performance have been reported, when using polymer–MWNT nanocomposite-based ETL. For example, Fournet et al. have investigated the
- nanocomposites [76]. They investigated Ag-doped ZnO (Ag:ZnO) and Ag:ZnO/PMMA nanocomposites for ETL applications in OLED. The pristine Ag:ZnO has an average particle size of ≈57 nm and the PMMA capping layer was ≈8 nm. Consequently, an increased rate of electron–hole recombination and an enhanced current density
- of ≈85% were obtained for optimized 10% Ag:ZnO/PMMA nanocomposite as compared to pristine Ag:ZnO. Enhancing the emissive layer The emissive layer is also known as the active luminescent region of an LED, where electron–hole recombination occurs. Light-emitting diodes and OLED are capable of emitting
An overview of microneedle applications, materials, and fabrication methods
Beilstein J. Nanotechnol. 2021, 12, 1034–1046, doi:10.3762/bjnano.12.77
- materials such as polymethylmethacrylate (PMMA) or SU-8 epoxy resin chemically amplified resist. The former is a positive-tone photoresist in which chemical bonds undergo scission upon exposure to the UV light, rendering the exposed regions of the pattern more soluble in the developer. For negative resists
- , moulding, and casting steps, forming polymer microneedles with a drug loaded onto their tips [72]. Elsewhere, transparent polymer microneedles were made in PMMA using a hot embossing process. First the master microneedle array, 250 μm high, was fabricated by a combination of isotropic and anisotropic
A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope
Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52
- heavier ions of similar energies [111]. A number of measurements have been made of the dose required to achieve HIBL full exposure of EBL-standard HSQ and PMMA resists, consistently finding that compared with electrons, one to two orders of magnitude lower doses of helium ions are required [114][115][116
- nanoimprint. In another HIBL-related study, helium ion irradiation was used to induce varying degrees of cross-linking of aromatic self-assembled monolayers supported on a gold substrate, followed by removal of the non-cross-linked regions by adhesion to a PMMA film [112]. This leaves the exposed (cross
Properties of graphene deposited on GaN nanowires: influence of nanowire roughness, self-induced nanogating and defects
Beilstein J. Nanotechnol. 2021, 12, 566–577, doi:10.3762/bjnano.12.47
- copper foil with methane gas as the precursor [31]. Next, graphene was transferred onto GaN NWs substrates. Due to low adhesive forces between graphene and corrugated substrates, the most common method to transfer graphene with the use of poly(methyl methacrylate) (PMMA) polymer could not be applied for
Exploring the fabrication and transfer mechanism of metallic nanostructures on carbon nanomembranes via focused electron beam induced processing
Beilstein J. Nanotechnol. 2021, 12, 319–329, doi:10.3762/bjnano.12.26
- the Ag layer by putting it into a 1 M Fe(NO3)3 solution for 24 h, the sample was protected by a 400 nm thick layer of poly(methyl methacrylate) (PMMA). In a next step, the CNM/EBID/PMMA hybrid structure was transferred onto a SiO2 substrate. Finally, the PMMA was dissolved in acetone. The results for
- solution within 10 min. Apparently the Fe(NO3)3 solution is responsible for the observed effect. It might be possible that the Fe(NO3)3 solution is able to diffuse through possible ruptures in the CNM or the PMMA layer. This diffusion process might lead to the dissolution/reduction of the iron structures
- protecting layer of PMMA with an overall thickness of ca. 400 nm. First, a layer of low-molecular-weight PMMA (35 ku), then, a layer of high-molecular-weight PMMA (996 ku) were spin cast each for 1 min at 4000 rpm and cured on a hot plate at 363 K for 5 min. The 300 nm thick silver layer was removed after
The patterning toolbox FIB-o-mat: Exploiting the full potential of focused helium ions for nanofabrication
Beilstein J. Nanotechnol. 2021, 12, 304–318, doi:10.3762/bjnano.12.25
- sheet was covered by a 500 nm thick PMMA layer. After etching the copper foil, the graphene sheet was transferred onto a SiN membrane with a regular grid of holes. The transfer process is described in detail elsewhere [52]. The SiN membrane was covered with a thin layer of gold, which allowed us to
- , we will assess the ultimate resolution of He ion beam machining to minimize the gap sizes. The gold flakes of approx. 30 nm thickness were wet-chemically synthesized on glass [60] and transferred to the target substrate via a PMMA-mediated method. On the target glass substrate, a thin layer of gold
Determination of elastic moduli of elastic–plastic microspherical materials using nanoindentation simulation without mechanical polishing
Beilstein J. Nanotechnol. 2021, 12, 213–221, doi:10.3762/bjnano.12.17
- finite element method [14][15][16][17][18][19][20][21][22][23][24][25]. Using finite element simulation, Li et al. found that both loading curve and unloading curve at any depth can be generated from one indentation depth by scaling P ∝ h2 for the indentation tests of PMMA thin films with a Berkovich
Application of contact-resonance AFM methods to polymer samples
Beilstein J. Nanotechnol. 2020, 11, 1714–1727, doi:10.3762/bjnano.11.154
- on imprecise parameters such as the tip position on the cantilever. This article shows quantitative CR measurements on polymer films of polystyrene (PS), poly(methyl methacrylate) (PMMA), and poly(n-butyl methacrylate) (PnBMA), as well as glass. Current analysis methods are simplified to a point that
- modulus larger than 1 GPa, such as PS or PMMA. Before testing Equation 16 in experiments, two of its properties are worth being highlighted. First, for αH ≫ 1, that is, for = ks ≫ kc, fn tends to where the numerical approximation has been calculated for the first mode, that is, This confirms that, for a
- position on the sample. The standard deviation of the six measurements performed at each force is typically between 0.1 and 1.5 kHz. Figure 6 shows the CR frequency in the first mode of a PPP-FMAuD cantilever as a function of the force F on glass, bulk PS and bulk PMMA, fitted with Equation 16, where the
Out-of-plane surface patterning by subsurface processing of polymer substrates with focused ion beams
Beilstein J. Nanotechnol. 2020, 11, 1693–1703, doi:10.3762/bjnano.11.151
- materials over the entire depth of their penetration path in a target. In our recent work [4], we demonstrated that, in addition to the direct surface patterning by the abovementioned techniques, the radiation damage generated by He+ FIB in the bulk of poly(methyl methacrylate) (PMMA) substrates can be used
- the PMMA polymer under ion irradiation [5][6][7]. The most important physical and chemical phenomena behind this material modification include scission and cross-linking of polymer chains, which can occur simultaneously, as well as the formation of volatile molecules and their desorption from the
- PMMA surface essentially intact and provides a new route to their out-of-plane patterning, which is interesting for a range of thin film applications. In the current work, we extend our study to the effects of the ion mass by irradiating PMMA substrates with He+, Ne+, and Ga+ ions, and to the role of
Wafer-level integration of self-aligned high aspect ratio silicon 3D structures using the MACE method with Au, Pd, Pt, Cu, and Ir
Beilstein J. Nanotechnol. 2020, 11, 1439–1449, doi:10.3762/bjnano.11.128
- nanoparticles and a poly(methyl methacrylate) (PMMA) patterning were etched in a diluted HF/H2O2 solution for 10 min. The process was a single-wafer bath process and can be scaled up to a batch process easily. As a reference, one wafer with gold nanoparticles was etched in a HF solution (1.73 mol/L) without the
- the H2 formation during the silicon etching. This indicates that the reactions are at least partially within the second etching regime (where n = 2). Figure 3 shows a microscope image of a wafer with Au nanoparticles after wet etching. The PMMA masking layer is still on top of the wafer. The resist
- contrast to the previous experiments, the Ir samples were not integrated on the wafer-level. The Ir nanoparticles were deposited with ALD on top of rectangular silicon dies. These dies were not annealed for particle formation and had no additional PMMA masking layer. The Ir samples were handled and wet
Effect of localized helium ion irradiation on the performance of synthetic monolayer MoS2 field-effect transistors
Beilstein J. Nanotechnol. 2020, 11, 1329–1335, doi:10.3762/bjnano.11.117
- synthesized using a CVD microreactor method, described in detail in [33], directly on 285 nm SiO2/Si substrates, which also served as the back-gate in the FET configuration. MoS2 flakes were contacted with electrodes using standard electron beam lithography on polymethyl methacrylate (PMMA) resist, followed
Structure and electrochemical performance of electrospun-ordered porous carbon/graphene composite nanofibers
Beilstein J. Nanotechnol. 2020, 11, 1280–1290, doi:10.3762/bjnano.11.112
- are incompatible with PAN, such as polystyrene (PS), poly(ʟ-lactic acid) (PLLA) and poly(methyl methacrylate) (PMMA) [20][21][22][23]. During the carbonization process at a high temperature, PAN and the blended polymers undergo phase separation, forming a large number of pores which increases the
An atomic force microscope integrated with a helium ion microscope for correlative nanoscale characterization
Beilstein J. Nanotechnol. 2020, 11, 1272–1279, doi:10.3762/bjnano.11.111
- have previously been difficult to obtain as sample preparation of such samples for SEM or TEM are often incompatible with the needs of high-resolution AFM measurements. AFM is also useful in assisting helium ion beam lithography. Many resists, including poly(methyl methacrylate) (PMMA), have higher
- to be navigated onto the region of interest (Figure 2b,c) to perform AFM topography imaging (Figure 2d). PMMA has traditionally been used as a positive resist in electron beam lithography. Helium ion beam lithography has emerged as a powerful technique to achieve even smaller feature size thanks to
- higher resist sensitivity, reduced proximity effect and small spot size [15]. Upon ion beam exposure, chain scission occurs leaving the exposed region soluble in a suitable developer. Very high ion doses also break short side chains that later cross-link, allowing PMMA to be also used as a negative
Templating effect of single-layer graphene supported by an insulating substrate on the molecular orientation of lead phthalocyanine
Beilstein J. Nanotechnol. 2020, 11, 814–820, doi:10.3762/bjnano.11.66
- . Single-layer graphene was synthesized by chemical vapor deposition (CVD) on a copper substrate and transferred by a standard technique using poly(methyl methacrylate) (PMMA) onto a SiO2 (300 nm)/Si substrate as reported elsewhere [30]. This process is optimized with regard to minimal PMMA contamination
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