PhD in Sciences – specializing in Physics, master in Physics – specializing in advanced materials for nano and micro technologies and degree in Physics.
Development of a force and deformation sensitive skin for biomedical devices.
The present project will develop nanostructured materials for application in endoscopes to provide force and deformation sensing functionality. The main objective of the present work consist in the development of piezoresistive sensors based both on polymer composites that can be applied by printing technologies and stretchable thin films serving as electrodes and/or piezoresistive sensors themselves, depending on their nanostructured morphology.
a) Schematic representation of the thin film microstructural features, b) SEM cross-section micrographs of the sputtered Ti-Ag thin film and c) Electromechanical response of samples.
PhD and Degree in Physics, Master in Materials Engineering
Novel materials and concepts for advanced rechargeable lithium-ion batteries
The main objective of my work is developing solid state high energy density lithium-ion rechargeable batteries based on: conventional fabrication and printing technologies. The investigation will focus on the development of materials for anode, cathode and separators with superior electrochemical, thermal and mechanical properties and cyclability.
Thus, novel batteries will be produced with improved performance characteristics, higher energy density and security, longer cycle lives, lower environmental impacts and new battery designs.
Left: Microstructure of the P(VDF–TrFE) membranes crystallized at room temperature. Surface characteristics of the samples with 72% (a) and 80% (b) porosity and cross-section details, respectively in (c) and (d). Insets in the figure (c) and (d) exhibits pore size distribution of the membranes. The membranes were obtained from 15/85 and 5/95 polymer/solvent ratios, respectively.Right: Cycling performance (delivered capacity: solid squares; coulombic efficiency: open squares) of Li/Sn-C anode half-cells containing Li+-conducting, P(VDF-TrFE) separators swollen in 1M LiPF6-EC/DMC(1:1 in weight) electrolyte solution at room temperature. Discharge rate: C/10-2C. Charge rate: C/10. Room temperature.
PhD in Physics and Integrated Master in Biomedical Engineering
Tailoring electro-mechanically active materials for tissue engineering applications
Proliferation, growth and differentiation of specific cells can be promoted and/or improved by the use of active materials. In particular, piezoelectric materials allow incorporating electrical and mechanical stimuli to the cells. This is a recent paradigm with large potential in tissue engineering applications. This work will evaluate the influence of surface electrical charge, dimensionality and surface properties of electroactive materials on biological response of specific cells such as osteoblast, fibroblast, myoblast and mesenchymal stem cells under static and dynamic conditions. Piezoelectric polymers will be prepared with novel architectures and tailored characteristics and the effect in cell response will be evaluated. Poly(vinylidene fluoride) and copolymers, poly(L-lactic acid) and polyhydroxybutyrate will be used as piezoelectric materials. Surface treatments will be implemented (specific proteins such as fibronectin and elastin, gelatin or conductive polymers) to increase cell response. The work is based on previous highly competitive research performed by the candidate (see addendum).
(a) Influence of polarization and morphology of electroactive poly(vinylidene fluoride) on the biological response of myoblast cells for skeletal muscle tissue engineering; (b)Influence of the polarization of electroactive poly(vinylidene fluoride) on the biological response of cells cultivated under static and dynamic conditions.
PhD in Electronic and Computer Engineering, Master and Degree in Industrial Electronics at the University of Minho.
Printed solutions for tactile sensor applications
Printed electronics is an emerging and new technology with the potential to revolutionize the fabrication of electronic devices. In this project, intrinsic advantages of printing technologies are explored in order to obtain low cost and flexible solutions customized for tactile sensor applications.
Several printing techniques like inkjet printing, screen printing, and spray painting where used to build all-printed circuits for signal acquisition, filter, and processing. Enabling signal treatment and optimization for the selected application. Furthermore, with the use of printed sensors, an all-printed solution can be implemented in one single package, towards the achievement of a fully integrated sensing system.
a) Schematic representation of the all-printed circuits used for signal a) acquisition, b) filtering, and c) processing from the piezoresistive pressure sensors.
PhD. in Science - Physics (2013), Master in Physics (2009) and Degree in Physics and Chemistry (2006) at the University of Minho.
Polymer based membranes for energy storage systems and water purification devices
My work is focused on the development of polymer based membranes for energy storage systems (1a) and for water purification devices (1d).
Nanocomposites of polyvinylidene fluoride (PVDF) with active nanofillers are processed by several techniques: thermally induced phase separation (TIPS), non-solvent induced phase separation (NIPS), spin coating and electrospinning. Their morphological (1c), structural, thermal, mechanical, electrical and electrochemical (1b) properties are evaluated in order to assess their performances in view of the intended application.
a) Squematic representation of a charge/discharge mechanism of a secondary battery; b) Galvanostatic charge-discharge curves of P(VDF-TrFE) at different scan rate; c) Cross section SEM picture of a porous membrane of P(VDF-TrFE); d) Porous membrane of P(VDF-TrFE) for water filtration.
PhD. in Materials Engineering (2015), Master in Materials Engineering
Application of Magnetoelectric Nanocomposites Based on Electroactive Polymers in Energy Harvesting Microsystems, Sensors and Actuators
This work can be divided into two main areas: developing of new material composites for improving the magnetoelectric response and the application of the materials for design of new electromagnetic generator shapes, which optimize the harvested power based on those materials, and for the application in the field of sensors and actuators.
(a) Laminate configuration and respectively magnetization and polarization orientation; (b) Measured αME magnetoelectric coefficient with the applied dc magnetic field.
Pedro Filipe Ribeiro da Costa
PhD. in Materials Engineering
Development of thermoplastic elastomer matrices and composites with large deformation for energy harvesting solutions
After study in piezoresistive sensors based in thermoplastic elastomers with large deformation and high piezoresistive sensibility during the PhD thesis, we use these materials to produce electrical energy through by the capacity variation on the dielectric elastomers. Is required an electronic circuit to provide, in first step, and harvesting electrical energy, posteriorly, on every stress-strain cycle of the dielectric elastomers. The optimization of the dielectric elastomers generators and electronic circuit is the key to maximize the energy harvesting.
Energy harvesting cycle of a DEG and mechanical configuration of wave energy harvesting.
Pedro Libânio Martins
PhD. and Master degree in Science - Physics, Degree in Physics and Chemistry-Teaching course
Magnetoelectric nanocomposites based on electroactive polymers
Polymer-based magnetoelectric (ME) materials are an interesting, challenging and innovative research ﬁ eld, that will bridge the gap between fundamental research and applications in the near future.
In this project are developed novel polymeric magnetoelectric sensors based on high performance magnetoelectric composites. The selected materials are improved/evaluated for sensor/actuator fabrication and integrated into devices: magnetic field sensors, current sensors, liquid level sensors, flow sensors and energy harvesting. Those devices have a strong and eminent possibility of technology transfer with the local industry with which we are collaborating.
(I) Representation of the Magnetoelectric magnetic field sensing mechanism. (II) Schematic representation of the Vitrovac/Epoxy/PVDF Magnetoelectric composite (a) and its ME response (c) after optimization (b) that pave the way for its incorporation into technological applications such as magnetic sensors (d).
PhD. in Integrated Master in Biomedical Engineering
Optimization of iron oxide-based porous magnetic silica spheres for histidine tagged proteins capture in large scale and lab-on-a-chip applications
The increasing number of large scale and lab-on-a-chip technologies for (bio)chemical applications based on the separation of biological entities, lead to the growing interest on functionalized magnetic nanoparticles. This project will evaluate the capture, transport, isolation and detection of histidine rich proteins on porous magnetic silica (PMS) spheres via coordinate bonding using transition metal ions as anchoring points. PMS will be synthesized and filled with superparamagnetic iron oxide nanoparticles. PMS spheres will be characterized and their magnetophoresis behavior studied. The surface of the PMS spheres will be functionalized and the binding capacity evaluated. A lab-on-a-chip system will be designed and fabricated, incorporating PMS and proteins recycling. Within the scope of related projects, therapeutic applications based on the PMS spheres will be studied.
Shematic representation of the microfluidic system for the capture and separation of histidine-rich proteins.
Polymer-based acoustic streaming system for microfluidic applications
Investigation of the feasibility and performance of acoustic streaming for the mixture of fluids at the microscale, generated with a polymer based piezoelectric transducer. The fabricated transducer comprises a 25 µm thick piezoelectric film of poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) with 85 nm thick electrodes of aluminium doped zinc oxide (AZO) on both sides of the piezoelectric film. The transducer is characterized by a piezoelectric coefficient |d33 | of 34 pC.N-1 and a transmittance higher than 75% throughout the visible light spectrum. The bottom and top electrodes have electrical resistivities of 3.5×10-3 Ω.cm and 11.3×10-3 Ω.cm, respectively. An electrical circuit was developed to optimize the electrical response of the system at the transducer resonance frequency of 48 MHz.The efficiency of the acoustic streaming phenomenon of the piezoelectric P(VDF-TrFE) transducer was studied by means of two diagnostic kits based on uric acid and nitrite.
(a) Photograph of the microfluidic system with the P(VDF-TrFE) piezoelectric transducer placed underneath the PDMS structure. The coaxial adapter is conected to the bottom and top of the AZO electrodes; (b) Gain in reaction time by acoustic streaming for different amplitudes of the signal applied to the contacts of the P(VDF-TrFE) piezoelectric film at a resonance frequency of 48MHz for the quantification of nitrite and uric acid in blood.
PhD and Integrated Master in Electrical Engineering and computers
Development of inkjet printed sensors
The development of printed sensors is a very recent and innovative line of research, long-awaited by the industry for its obvious advantages as a product.
Thus in this project is developed new sensors based in the print technology for measuring several greatness's, such as: force, strain, magnetic field, electrochemical effects etc. through the use of materials, new methods and new paint formulations.
This can be considered a pre-industrial development line, because they are used the same processes as industry, so is easily scalable and applicable in current production lines.
(a) Inkjet printed piezoresistive 5x4 matrix sensor; (b) Mechanical deformation signal and amplitude response of three sensors; (c) Schematic of the various layers which constitute the piezoresistive 5x4 matrix sensor; (d) Single sensor comparative dimensions with a hole of a needle; (d) Detailed view of the sensors active layer.
Development of electromechanical bioreactor for cell culture and tissue engineering
Currently, tissue engineering and cell culture in general is being exploring with the objective of the reconstruct tissues and organs100% compatible with the receptor. But despite the great advances in this research area we are still far from this goal.
This project aims to contribute to achieving this goal, trying to simulate the set of stimuli to which cells are subjected in their native environment, including: electrical, magnetic and mechanical stimuli. It is intended to promote the growth and differentiation of cells simulated as realistically as possible the its native environment in controlled conditions.
Moreover this development allows to significantly reduce the environmental footprint of research in this area, because it allows to reduce the use of animals as a way to simulate the native cell environment as well the associated economic costs.
(a) Bioreactor for the production of electrical-stimulation of cells prototype; (b) Bioreactor for the production of electromechanical-stimulation of cells prototype ; (c) Electromechanical Bioreactor in a real conditions of use.