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Author

Graça Minas

Bio: Graça Minas is an academic researcher from University of Minho. The author has contributed to research in topics: Lab-on-a-chip & Optical filter. The author has an hindex of 21, co-authored 163 publications receiving 1485 citations.


Papers
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Journal ArticleDOI
TL;DR: In this review, a selection of the most recent lithographic and non-lithographic low-cost techniques to fabricate microfluidic structures, focused on the features and limitations of each technique.

235 citations

Journal ArticleDOI
TL;DR: In this paper, the influence of the polymer/solvent mass ratio of the solution, the rotational speed of the spin-coater and the temperature of crystallization of the material has been investigated.
Abstract: Poly(vinylidene fluoride), PVDF, thin films have been processed by spin-coating with controlled thickness, morphology and crystalline phases. The influence of the polymer/solvent mass ratio of the solution, the rotational speed of the spin-coater and the temperature of crystallization of the films on the properties of the material has been investigated. It is shown that high-quality films with controlled thicknesses from 300 nm to 4.5 µm and with a controlled amount of electroactive crystalline phases can be obtained in a single deposition step, which allows tailoring the material characteristics for specific applications.

126 citations

Journal ArticleDOI
TL;DR: The study and optimization of epoxy-based negative photoresist (SU-8) microstructures through a low-cost process and without the need for cleanroom facility is presented, and the Ultraviolet Rays (UV) exposure equipment can replace the more expensive and less available equipment.
Abstract: The study and optimization of epoxy-based negative photoresist (SU-8) microstructures through a low-cost process and without the need for cleanroom facility is presented in this paper. It is demonstrated that the Ultraviolet Rays (UV) exposure equipment, commonly used in the Printed Circuit Board (PCB) industry, can replace the more expensive and less available equipment, as the Mask Aligner that has been used in the last 15 years for SU-8 patterning. Moreover, high transparency masks, printed in a photomask, are used, instead of expensive chromium masks. The fabrication of well-defined SU-8 microstructures with aspect ratios more than 20 is successfully demonstrated with those facilities. The viability of using the gray-scale technology in the photomasks for the fabrication of 3D microstructures is also reported. Moreover, SU-8 microstructures for different applications are shown throughout the paper.

91 citations

Journal ArticleDOI
TL;DR: An overview of the microfabrication techniques is given, especially for biomedical applications, as well as a synopsis of some design considerations regarding microfluidic devices.
Abstract: Since the first microfluidic device was developed more than three decades ago, microfluidics is seen as a technology that exhibits unique features to provide a significant change in the way that modern biology is performed. Blood and blood cells are recognized as important biomarkers of many diseases. Taken advantage of microfluidics assets, changes on blood cell physicochemical properties can be used for fast and accurate clinical diagnosis. In this review, an overview of the microfabrication techniques is given, especially for biomedical applications, as well as a synopsis of some design considerations regarding microfluidic devices. The blood cells separation and sorting techniques were also reviewed, highlighting the main achievements and breakthroughs in the last decades.

89 citations

Journal ArticleDOI
25 Nov 2020-Small
TL;DR: Recent advances on OoC platforms, particularly on the preclinical validation of nanomaterials designed for cancer, as well as the current challenges and possible future directions for an end-use perspective are discussed.
Abstract: Despite the progress achieved in nanomedicine during the last decade, the translation of new nanotechnology-based therapeutic systems into clinical applications has been slow, especially due to the lack of robust preclinical tissue culture platforms able to mimic the in vivo conditions found in the human body and to predict the performance and biotoxicity of the developed nanomaterials. Organ-on-a-chip (OoC) platforms are novel microfluidic tools that mimic complex human organ functions at the microscale level. These integrated microfluidic networks, with 3D tissue engineered models, have been shown high potential to reduce the discrepancies between the results derived from preclinical and clinical trials. However, there are many challenges that still need to be addressed, such as the integration of biosensor modules for long-time monitoring of different physicochemical and biochemical parameters. In this review, recent advances on OoC platforms, particularly on the preclinical validation of nanomaterials designed for cancer, as well as the current challenges and possible future directions for an end-use perspective are discussed.

63 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the main characteristics of the electroactive phases of polyvinylidene fluoride and copolymers are summarized, and some interesting potential applications and processing challenges are discussed.

2,242 citations

Journal ArticleDOI
TL;DR: This review will introduce the currently relevant microfabrication technologies such as replication methods like hot embossing, injection molding, microthermoforming and casting as well as photodefining methods like lithography and laser ablation for microfluidic systems and discuss academic and industrial considerations for their use.
Abstract: Polymers have assumed the leading role as substrate materials for microfluidic devices in recent years. They offer a broad range of material parameters as well as material and surface chemical properties which enable microscopic design features that cannot be realised by any other class of materials. A similar range of fabrication technologies exist to generate microfluidic devices from these materials. This review will introduce the currently relevant microfabrication technologies such as replication methods like hot embossing, injection molding, microthermoforming and casting as well as photodefining methods like lithography and laser ablation for microfluidic systems and discuss academic and industrial considerations for their use. A section on back-end processing completes the overview.

840 citations

Journal ArticleDOI
TL;DR: This review deals with the application of optical sensing systems for microfluidic devices, in the "off-chip approach" macro-scale optical infrastructure is coupled, while the "on- chip approach" comprises the integration of micro-optical functions into microfluidity devices.

434 citations