12 documents found, page 1 of 2
3D tubular constructs based on natural polysaccharides and recombinant polypept...
Rodrigues, Luísa Cidália Guimarães; Gomes, J. M.; Soares da Costa, Diana; Fernandes, Emanuel Mouta; Costa, R. R.; Rodríguez-Cabello, J. C.; Silva, S. S.The development of versatile tubular structures is critical for tissue engineering (TE) applications where vascularization is necessary. This study investigates the fabrication of tubular shaped biomaterials focused on chitosan (CHT) combined with alginate (ALG) and acemannan (ACE), known for their synergistic properties, including physical stability, antibacterial activity, and healing promotion. Translating t...
Fabrication of biocompatible porous SAIB/silk fibroin scaffolds using ionic liq...
Gonçalves, Cristiana; Gomes, J. M.; Maia, F. Raquel; Radhouani, Hajer; Silva, S. S.; Reis, R. L.; Oliveira, J. M.Sucrose acetate isobutyrate (SAIB) is a highly viscous hydrogel and presents many challenges for processing when its application in tissue engineering is envisioned. Herein, is proposed an innovative methodology by processing SAIB with ionic liquids (ILs), combined with silk fibroin (SF), to develop SAIB/SF scaffolds. Fourier Transform Infrared analysis confirmed SF and SAIB presence in the structures and the e...
Exploring the use of choline acetate on the sustainable development of α‑chitin...
Gomes, J. M.; Silva, Simone S.; Reis, R. L.This study proposes a green and innovative methodology for the exploitation of natural polymers, namely chitin, using solvents with reduced toxicity for the creation of porous structures with the potential to be used in the biomedical field. Chitin is a promising biopolymer for the design of biodegradable constructs and encouraging developments on its processing have been achieved using ionic liquids (ILs). How...
Green pathway for processing non-mulberry antheraea pernyi silk fibroin/chitin-...
Silva, Simone S.; Gomes, J. M.; Vale, Ana Catarina; Lu, Shenzhou; Reis, R. L.; Kundu, Subhas CSilk protein fibroin (SF)-based matrices from non-mulberry, and mulberry silkworms are used for different applications in regenerative medicine. Silk fiber spun by the wild non-mulberry silkworm Antheraea pernyi (Ap) is also a promising biomedical material, due to the presence of the inherent tripeptide sequence of Arginine-Glycine-Aspartic acid (RGD) on the protein fibroin sequences. However, SF derived from t...
Marine-derived polymers in ionic liquids: architectures development and biomedi...
Silva, Simone S.; Gomes, J. M.; Rodrigues, Luísa Cidália Guimarães; Reis, R. L.Marine resources have considerable potential to develop high-value materials for applications in different fields, namely pharmaceutical, environmental, and biomedical. Despite that, the lack of solubility of marine-derived polymers in water and common organic solvents could restrict their applications. In the last years, ionic liquids (ILs) have emerged as platforms able to overcome those drawbacks, opening ma...
A Low-Cost Flexible-Platform (LCFP) for characterization of photodetectors
Gomes, J. M.; Correia, J. H.; Carmo, João Paulo PereiraThis paper presents a Low-Cost Flexible-Platform (LCFP) for measuring and characterizing photodetectors. This LCFP can characterize simultaneously up to 16 photodetectors and is composed by two main electronic circuit boards: a Transimpedance Amplifier Board (TIAB) and a Development Board (DevB). The TIAB was designed and optimized to reduce the noise increase, in order to convert photocurrents into voltages an...
The effect of microlenses in photodiodes' dark current measurement
Rocha, R. P.; Maciel, Marino Jesus Correia; Gomes, J. M.; Correia, J. H.; Carmo, João Paulo PereiraThis paper presents the influence of microlenses (MLs) in the photodiodes' (PD) dark current. A MLs array was aligned and fabricated directly on top of the PDs and their effects on the dark current was measured. Two square PDs with the sides measuring 24 and 240 mu m were evaluated under two different reverse bias voltages, 0 and -4 V. For the 24 mu m PD, when the MLs were fabricated on its surface, the dark cu...
Optical filters for stereoscopic image sensors
Maciel, Marino Jesus Correia; Silva, Manuel Fernando Ribeiro; Rocha, R. P.; Carmo, João Paulo Pereira; Gomes, J. M.; Correia, J. H.This paper presents optical filters for integration on stereoscopic image sensors. The filters must cover each one of primary colors within the visible, in order to yield a passband around the respective wavelengths. Dielectric materials based on SiO 2 and TiO 2 were used due to their compatibility with silicon. The best simulation with only 3 dielectric layers resulted in optical filters with full width at hal...
Fabrication of AZ4562 refractive microlenses array for light enhancement on opt...
Rocha, R. P.; Carmo, João Paulo Pereira; Correia, J. H.; Gomes, J. M.This paper presents the fabrication of an array of high aspect ratio photoresist based refractive microlenses (ML) using photolithography and thermal reflow. First, and in order to evaluate and predict the MLs optical properties and physical dimensions, finite element analysis was done. These simulations helped to design the super high resolution chrome on soda lime glass photomask as well as the parameters for...
Microlenses array made with AZ4562 photoresist for stereoscopic acquisition
Rocha, R. P.; Carmo, João Paulo Pereira; Gomes, J. M.; Belsley, M.; Correia, J. H.In this paper is presented a fabrication process for obtaining refractive microlenses arrays with high reproducibility and low cost. This process was specifically optimized for the AZ4562 photoresist. Functional prototypes of microlenses arrays with dimensions in the range of 30 m, 4.9 mm and 5 m for width, length and thickness, respectively, were fabricated and tested. The pre-thermal reflow spacing between ...