16 documents found, page 1 of 2
Optimizing acoustic pressure fields in SAW microfluidic devices: A numerical st...
Amorim, Débora; Dinis, Hugo Daniel Costa; Minas, Graça; Sousa, Patrícia C.; Abreu, Carlos; Catarino, Susana OliveiraSurface acoustic wave-based microfluidic devices have gained substantial attention for their effectiveness in manipulating, detecting, and quantifying biological samples. These systems utilize interdigitated transducers deposited on piezoelectric substrates to generate acoustic fields within microchannels. This study presents a comparative analysis of acoustic pressure fields generated using different piezoelec...
Modelling the heat distribution in organ-on-a-chip systems using integrated mic...
Ferreira, Gabriel Malheiro; Sousa, Patrícia C.; Catarino, Susana Oliveira; Minas, Graça[Excerpt] Microfluidic systems with integrated heating transducers are of growing interest for applications in biochemical sensing, lab-on-a-chip and organ-on-a-chip (OoC) technologies [1]. Particularly, in OoC systems, temperature monitoring is crucial to maintain the cultured cells in a well-defined microenvironment for proper growth [2]. This monitoring can be achieved through temperature control systems com...
A review of SAW-based micro- and nanoparticle manipulation in microfluidics
Amorim, Débora; Sousa, Patrícia C.; Abreu, Carlos; Catarino, Susana OliveiraSurface acoustic wave (SAW)-based microfluidics has emerged as a promising technology for precisely manipulating particles and cells at the micro- and nanoscales. Acoustofluidic devices offer advantages such as low energy consumption, high throughput, and label-free operation, making them suitable for particle manipulation tasks including pumping, mixing, sorting, and separation. In this review, we provide an o...
Design of a CMOS Current-to-Frequency Converter for Optical pH Sensing in a cul...
Ferreira, Gabriel Malheiro; Santos, André Alves dos; Sousa, Patrícia C.; Catarino, Susana Oliveira; Minas, GraçaIn organ-on-a-chip systems, accurate pH sensing is essential for an effective physiological control of the cells’ culture media. In this work, there was developed a current-to-frequency (IF) converter integrated with a CMOS photodiode for pH quantification of cells’ culture medium. The selection of the optimal features for the converter configuration, such as input current and resolution, was based on initial c...
Physicochemical Characterisation of Olive Mill Wastewaters Based on Extraction ...
Afonso, Inês Santos; Duarte, Cristina; Afonso, Maria João A.P.S.; Ribeiro, António E.; Amaral, Joana S.; Sousa, Patrícia C.; Lima, Rui A.Olive mill wastewaters (OMWW) generated during olive oil extraction represent a significant environmental challenge due to their high organic matter content, acidic pH, phenolic content, and toxicity. Their composition varies widely depending on the extraction method and remains difficult to treat, particularly for small-scale producers lacking access to complex infrastructure. This study evaluates the combined...
Complementary metal oxide semiconductor-based optical detection system for flui...
Santos, André Alves dos; Ferreira, Gabriel Malheiro; Sousa, Paulo Jorge Teixeira; Sousa, Patrícia C.; Catarino, Susana Oliveira; Minas, GraçaAccurate pH sensing is essential for the effective physiological control of the culture media in organ-on-a-chip (OoC) systems. This work proposes a miniaturized optical detection system, based on optical transmittance, for pH level quantification of the EGM™-2 Endothelial Cell Growth Medium-2 BulletKit™ culture medium. Firstly, using a commercial spectrophotometric setup, a set of wavelengths (500, 560, and 60...
Platinum resistance temperature detectors for biomedical applications
Retolaza, Aritz; Sotgiu, Edoardo; Ferreira, Gabriel M.; Sousa, Paulo J.; Catarino, Susana Oliveira; Minas, Graça; Alves, Filipe; Dias, Rosana[Excerpt] The rapid advancement in biosensing devices is driven by the growing need to continuously monitor human health data and predict the onset of chronic diseases at an early stage. These devices leverage a variety of sensors designed for continuous monitoring of physiological and biochemical markers, often integrated into wearable or implantable patches [1]. Among these sensors, the temperature sensors ar...
Fabrication and electrical characterization of low-temperature polysilicon film...
Mota, Filipa C.; Garcia, Inês S.; Retolaza, Aritz; Santos, Dimitri E.; Sousa, Patrícia C.; Aguiam, Diogo E.; Dias, Rosana A.; Calaza, CarlosThe development of low-temperature piezoresistive materials provides compatibility with standard silicon-based MEMS fabrication processes. Additionally, it enables the use of such material in flexible substrates, thereby expanding the potential for various device applications. This work demonstrates, for the first time, the fabrication of a 200 nm polycrystalline silicon thin film through a metal-induced crysta...
Numerical simulation, fabrication, and characterization of a heating system for...
Ferreira, Gabriel Malheiro; Azevedo, Filipe M.; Sousa, Paulo Jorge Teixeira; Pinto, Vânia Cristina Gonçalves; Catarino, Susana OliveiraIn an organ-on-a-chip (OoC) device, temperature control is essential for a well-controlled and human representative microenvironment. This work presents the design, numerical simulation, fabrication and characterization of three aluminium microheater geometries for temperature control into an OoC device. Two of them are circular-based, with different curvature filleting angles and different line widths, and the...
A numerical study of the heat distribution generated by a microheater in an org...
Ferreira, Gabriel Malheiro; Sousa, Paulo Jorge Teixeira; Pinto, Vânia Cristina Gonçalves; Catarino, Susana Oliveira; Sousa, Patrícia C.; Minas, GraçaIn an organ-on-a-chip (OoC), temperature must be kept stable for a well-controlled and human representative microenvironment. This work presents the numerical simulation of a microheater to be integrated in a polydimethylsiloxane chamber that will comprise an OoC. Numerical simulations were performed to evaluate the heat distribution, considering the fluid flow and its direction, the microheater and substrate m...