Cyclic olefin copolymer plasma millireactors

Dual Surface Architectonics for Directed Self-Assembly of Ultrahigh-Resolution Electronics

The directed self-assembly of electronic circuits using functional metallic inks has attracted intensive attention because of its high compatibility with extensive applications ranging from soft printed circuits to wearable devices. However, the typical resolution of conventional self-assembly technologies is not sufficient for practical applications in the rapidly evolving additively manufactured electronics (AMEs) market. Herein, an ultrahigh-resolution self-assembly strategy is reported based on a dual-surface-architectonics (DSA) process. Inspired by the Tokay gecko, the approach is to endow submicrometer-scale surface regions with strong adhesion force toward metallic inks via a series of photoirradiation and chemical polarization treatments. The prepared DSA surface enables the directed self-assembly of electronic circuits with unprecedented 600 nm resolution, suppresses the coffee-ring effect, and results in a reliable conductivity of 14.1 ± 0.6 µΩ cm. Furthermore, the DSA process enables the layer-by-layer fabrication of fully printed organic thin-film transistors with a short channel length of 1 µm, which results in a large on-off ratio of 10⁶ and a high field-effect mobility of 0.5 cm²  V^-1  s^-1 .

Disposable DNA Amplification Chips with Integrated Low-Cost Heaters

Fast point-of-use detection of, for example, early-stage zoonoses, e.g., Q-fever, bovine tuberculosis, or the Covid-19 coronavirus, is beneficial for both humans and animal husbandry as it can save lives and livestock. The latter prevents farmers from going bankrupt after a zoonoses outbreak. This paper describes the development of a fabrication process and the proof-of-principle of a disposable DNA amplification chip with an integrated heater. Based on the analysis of the milling process, metal adhesion studies, and COMSOL MultiPhysics heat transfer simulations, the first batch of chips has been fabricated and successful multiple displacement amplification reactions are performed inside these chips. This research is the first step towards the development of an early-stage zoonoses detection device. Tests with real zoonoses and DNA specific amplification reactions still need to be done.

Investigation of using Cyclic Olefin Copolymer as Neural Electrode

Cyclic olefin copolymer (COC) is a polymer that has recently been attracting attention in optics and microfluidic applications due to its high solvent resistance, biocompatibility, thermoplasticity, and optical transparency. It also has very low water absorption rate, which makes COC a very good candidate for packaging material for implantable neural prosthetic devices. In this study, we investigated the possibilities of fabricating COC into a neural electrode. We started by heat-compressing COC pellets to form films. After oxygen plasma surface treatment, a thin layer of gold was deposited. Then, a standard photolithography technique was used to pattern the gold. Finally, the paths were insulated using an extra film of COC. The validity of the fabricated electrode was confirmed by metal contact test and soak testing in PBS solution for a week.

Fabrication and Evaluation of Cyclic Olefin Copolymer Based Implantable Neural Electrode

OBJECTIVE

The purpose of this paper is to establish fabrication method of cyclic olefin copolymer(COC)-based neural electrode.

METHODS

The fabrication started with preparing COC pellets into COC films by compression molding. Metal layers were deposited on the COC film and attached to a silicon wafer. Laser ablation was used to cut the outer edges and mark alignment keys. The metal layers were patterned using standard photolithography procedures. Finally, the isolated electrodes were laminated. To ensure that the resulting electrode is safe and suitable for long-term implants, in vitro biocompatibility test, impedance evaluation, accelerated soak test, and repeated bend test were conducted.

RESULTS

Cytotoxicity test and elution test confirmed the biocompatibility in vitro. The basic performance was not hindered compared to other polymer-based electrodes, and the longevity of the electrode was validated by accelerated soak test. However, repeated bend test revealed that the material might not be suitable for applications where constant bending is required.

CONCLUSION

The COC-based neural electrode was successfully fabricated. The material showed several merits such as biocompatibility, thermoplasticity, low water absorption rate, and high transparency, but should be limited to applications where repeated bending is not required.

SIGNIFICANCE

Electrical circuits in implantable prosthetic devices must be hermetically encapsulated for a long period of time. Material such as COC with extremely low water absorption rate could have a significant impact on the longevity of these devices.

Beyond electrolysis: old challenges and new concepts of electricity-driven chemical reactors

With renewable electricity becoming the most widely available, versatile energy form on Earth, the electricity-driven chemical reactors will play crucial role in the transition to green, environmentally-neutral manufacturing of fuels and chemicals.

FISH in chips: turning microfluidic fluorescence in situ hybridization into a quantitative and clinically reliable molecular diagnosis tool

Microfluidic systems bear promise to provide new powerful tools for the molecular characterization of cancer cells, in particular for the routine detection of multiple cancer biomarkers using a minute amount of the sample. However, taking miniaturized cell-based assays into the clinics requires the implementation and validation of complex biological protocols on chip, as well as the development of disposable microdevices produced at a low cost. Based on a recently developed microfluidic chip made of Cyclic Olefin Copolymer for cell immobilization with minimal dead volume and controlled shear stress, we developed a protocol performed entirely in the liquid phase, allowing the immobilization and fixation of cells and their quantitative characterization by fluorescence in situ hybridization. We demonstrated first in cell lines and then in two clinical case studies the potential of this method to perform quantitative copy number measurement and clinical scoring of the amplification of the ERBB2 gene, a decisive biomarker for the prescription of HER2+ related targeted therapies. This validation was performed in a blind protocol in two clinical case studies, in reference to the gold standard and clinically used method based on glass slides. We obtained a comparable reproducibility and a minor difference in apparent amplification, which can be corrected by internal calibration. The method thus reaches the standard of robustness needed for clinical use. The protocol can be fully automated, and its consumption of samples and DNA probes is reduced as compared to glass slide protocols by a factor of at least 10. The total duration of the assay is divided by two.