Roll-to-roll fabrication of superhydrophobic pads covered with nanofur for the efficient clean-up of oil spills

• Patrick Weiser,
• Robin Kietz,
• Marc Schneider,
• Matthias Worgull and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2022, 13, 1228–1239, doi:10.3762/bjnano.13.102

• realized because of the limitations of conventional hot embossing regarding structurable area. The structured film is subsequently processed into an exemplary product, that is, so-called nanopads; polymeric sandwiches of polypropylene film covered with nanofur and filled with an oil-absorbing material

• . These are well-suited for the cleanup of small oil spills. Keywords: hot embossing; lotus effect; nanofur; nanopads; oil spill cleanup; oil water separation; roll-to-roll; R2R; superhydrophobicity; Introduction Self-cleaning surfaces utilizing the famous lotus effect have gained significant importance

• steel plates serving as form inserts in a hot embossing machine [18]. However, in this case the fabrication is limited to areas of some square centimeters. These sizes are not sufficient for commercial applications. To overcome this hurdle and to allow for the cost-effective fabrication of thin

Fabrication and testing of polymer microneedles for transdermal drug delivery

• Vahid Ebrahiminejad,
• Zahra Faraji Rad,
• Philip D. Prewett and
• Graham J. Davies

Beilstein J. Nanotechnol. 2022, 13, 629–640, doi:10.3762/bjnano.13.55

• manufacturing processes for MNs is of considerable interest. This study reports a simple fabrication process for thermoplastic MNs from cycloolefin polymers (COP) using hot embossing on polydimethylsiloxane (PDMS) soft molds. COP has gained interest due to its high molding performance and low cost. The resin

• setting. Keywords: hot embossing; microneedles; penetration efficiency; thermoplastic polymers; two-photon polymerization; Introduction During the past two decades, MN devices have become a promising tool for transdermal drug delivery, vaccination, and point-of-care diagnostics [1][2]. MNs are a

• fabrication of MNs. The low manufacturing cost and desirable mechanical properties of medical-grade thermoplastics such as COPs make them a particularly attractive choice of materials [15][16]. MN thermoplastic replicas are readily fabricated using injection molding or hot embossing [17]. However, process

An overview of microneedle applications, materials, and fabrication methods

• Zahra Faraji Rad,
• Philip D. Prewett and
• Graham J. Davies

Beilstein J. Nanotechnol. 2021, 12, 1034–1046, doi:10.3762/bjnano.12.77

• biotherapeutics, drugs, and vaccines through the skin. A wide range of microneedle structure, design, geometry, and microneedle array densities is manufactured using different rapid prototyping and microfabrication technologies such as deep reactive ion etching (DRIE) [2], lithography [3], hot embossing [4], and

• . They can be made using micromoulding techniques, including hot embossing, which cannot be implemented for hollow microneedles because of residual debris in the lumen [5]. Microneedle materials, manufacturing methods and uses Overview of manufacturing methods Arguably, the most challenging problem for

• injection moulding [61], wet chemical etching [75], reactive ion etching [2][76], hot embossing [4][5], laser drilling [77], lithography plus electroforming [78][79], drawing lithography [80][81], two-photon polymerization [5][82], and 3D printing [83][84]. To date, DRIE of silicon; micromoulding

Preparation and characterization of polycarbonate/multiwalled carbon nanotube nanocomposites

• Claudio Larosa,
• Niranjan Patra,
• Marco Salerno,
• Lara Mikac,
• Remo Merijs Meri and
• Mile Ivanda

Beilstein J. Nanotechnol. 2017, 8, 2026–2031, doi:10.3762/bjnano.8.203

• serious thermal stability issues at the hot embossing temperature of PC. It has been suggested that the addition of MWCNTs can significantly change the mechanical properties of PC, as well as affect the crystallization behavior [5]. In former work, the effect of adding gold nanoparticles on the optical

Nano- and microstructured materials for in vitro studies of the physiology of vascular cells

• Alexandra M. Greiner,
• Adria Sales,
• Hao Chen,
• Sarah A. Biela,
• Dieter Kaufmann and
• Ralf Kemkemer

Beilstein J. Nanotechnol. 2016, 7, 1620–1641, doi:10.3762/bjnano.7.155

• order to give an overview of different microfabrication techniques, relevant examples for different approaches such as optical (photolithography [49]), mechanical (hot embossing [50] and surface cracking [51][52]) or chemical (replica molding [53][54], phase separation micromolding [55][56][57], gas

• using metals [58]. The surface structures made by photolithography are typically further used as a master structure for further processing. Hot embossing also replicates micro- and nanofeatures of master substrates. In that case, a thermoplastic material is pressed on the mold at a high temperature to

• form the topography of the features in the plastic. Similar to replica molding in soft lithography, features down to around 10 nm can be replicated. Like soft lithography hot embossing is a cheap method suitable for large-scale manufacturing of substrates [50]. In principle, it can be used with many

Large-scale fabrication of achiral plasmonic metamaterials with giant chiroptical response

• Morten Slyngborg,
• Yao-Chung Tsao and
• Peter Fojan

Beilstein J. Nanotechnol. 2016, 7, 914–925, doi:10.3762/bjnano.7.83

• ]. The original molds were used to make negative imprints by thermal nanoimprint lithography using the EVG520HE semi-automated hot embossing system. This was done in TOPAS 5013L-10 substrates under vacuum with a stamping pressure of 1.25 bar and at 160 °C using the original molds. Next a 30 nm film was