Job Offers
Research Areas
We are looking for motivated students, PhD students and scientists in the following research areas:
- Modeling polymer materials (Quantum chemistry, molecular dynamics, FEM)
- Synthesis and design of electroactive polymer materials and actuators.
- Physical and chemical characterization of polymer materials.
- Cyclic flow-electrode capacitor development
- Electromechanical characterization and validation of electroactive polymer actuators and sensors.
- Electromecahnical modelling of EAP materials (FEM, Electromechanicalmodels)
- Radiation damage of materials
- Biologially inspired robotics
- Image processing
- Applications of robotics
Positions
Euraxess Offers
PhD student position in Design and Implementation of CMOS Image Sensor for Medical Diagnostics
- Organization
- University of Tartu
- Research Field
- Engineering › Electronic engineering, Engineering › Microengineering
- Researcher Profile
- First Stage Researcher (R1)
- Deadline
- 15/02/2020 18:00 - Europe/Athens
- Location
- Estonia
- Type Of Contract
- Temporary
- Hours Per Week
- 40
- Job Status
- Full-time
- Requirements
- Languages
- ENGLISH: GoodSee the offer on Euraxess website.
Environment:
Intelligent Materials and Systems Laboratory is an interdisciplinary research group established in 2003 in University of Tartu, Institute of Technology. Our goal is, by bringing together knowledge from diverse fields of expertise, to develop new materials and their control and applications. Exploitation of innovative materials will in turn permit building devices, different and in many ways superior to conventional machines. The scientific background of our staff as well as the laboratory equipment permits research activities on the borderline of computational material science, material science, robotics, chemistry, computer science and electronics.
The candidate will work on the development of a novel CMOS Image sensor fabricated with standard CMOS processes, while maintaining their cost advantage. She/ He will work in close collaboration with experts from micro-electronic design.
Project Background: Camera technology has been made accessible to everyone today by the onset of digital cameras as end products. In the last decade, endoscopy detection systems emerged to be a new alternative to the traditional fiber optic endoscopy. These systems provide a non-invasive solution to patients suffering from middle ear infections and extends to those suffering from colon cancer, gastric ulcers and Chron’s disease [1]. The state-of-the-art endoscopy detection system includes a swallowable capsule and off-body receivers. However, they suffer from high power and challenges with integration of multi-functional image processing. In order to overcome these challenges, a full-custom chip design integrating sensors and processing on a single chip is proposed to be a viable solution. The onset of CMOS cameras in medical imaging sector have provided higher integration capability, lower power consumption, smaller die size, and lower cost compared to its major competitor, CCD cameras Active Pixel Sensors (APS) in Complementary Metal Oxide Semiconductor (CMOS) image sensors has made it straightforward to envision a camera-on-chip that integrates the pixel array comprising photodiodes and pixel electronics, electronics associated with timing and control, signal processing and analog to digital interface on a monolithic substrate. With this concept, CMOS cameras started to provide higher integration capability, lower power consumption, smaller area, and lower cost compared to its major competitor, CCD cameras [2]. These advantages of CMOS cameras have made them inevitable for portable and low-cost devices.
Objective:
The main objectives are to develop low cost CMOS image sensors in biomedical applications (targeted to diagnose middle ear infection: Otitis Media) and improve their performance by integrating novel circuits fabricated with standard CMOS process, while maintaining their cost advantage.
The main tasks for the candidate can be divided into three main axes detailed hereafter.
Task I Design of full-custom CMOS digital pixel sensor array integrated with novel readout integrated circuits
The occurrence of OM is caused due to the malfunction of Eustachian tube leading to accumulation of fluid behind the ear drum. This, in turn, causes growth of bacteria and virus. The two main complications that are misclassified by general practitioners (GPs) are Acute Otitis Media (AOM) due to bacteria and virus and Otitis Media with Effusion (OME) due to accumulation of fluid without presence of bacteria/virus. The standard diagnostic practice relies on a rigid device with large form factor namely otoscope. The existing gaps recognized are improper positioning and imaging by otoscope that leads to misclassification of OM. This leads to treatment of OM classifications (OME) that do not benefit from antibiotics, leading to development of antibiotic resistance. This stresses upon the necessity to establish a gold standard for diagnosis prior to initiating treatment.
In order to overcome the above limitations, the proposed diagnostic solution comprises a flexible microsystem with integrated contacts capable of manipulating a bio-inspired flexible silicon-based image sensor with improved auto-focus. The bio-inspired flexible involves thinning a standard CMOS Image sensor and transfer onto a flexible support. The candidate’s task will be confined to development of a low cost System-on-Chip (SoC) CMOS Image sensor integrated with novel readout circuits. The candidate will analyze the Active Pixel Sensor (APS) and Digital Pixel Sensor (DPS) designs in terms of their respective advantages and disadvantages, to decide the pixel level design and pixel sharing technique. In order to maintain the small die size, the number of transistors have to be kept as low as possible and reach a high fill factor and photon collection efficiency, without requiring extra circuit. The most important limiting factor in standard CMOS cameras is their noise floor will be optimized by implementation of offset and gain compensation techniques with low area overhead, for instance switched-capacitor correlated double sampling (CDS) circuits. The pixel-array sensors and noise-reduction and horizontal and vertical access readout circuits will be designed in Cadence Virtuoso with relevant CMOS process compatible technology. The performance parameters, Pixel-level simulation, ADC simulation and top-level simulation will be carried out.
Task II: Characterization of Fabricated Test Chip
Next, the fabricated test chip (bare die) will be characterized by an optical setup in terms of responsivity, sensitivity and dark current in response to varying light conditions, being the three most important performance parameters for standard CMOS Image sensor in low light imaging medical applications.
Task III: Development of Prototype demonstrator
A small camera prototype PCB will be developed by utilizing the characterization data of the fabricated test chip. The PCB design will include image collection hardware and communication between different parts of the board. The experimental measurements of performance parameters will be followed to capture images of the test patterns for an infected and healthy ear drum.
Key words: CMOS image sensors, CCD image sensors, CMOS cameras, event-detection, biomedical imaging, digital cameras, noise reduction circuits, CDS, correlated double sampling, Active Pixel Sensor, Digital Pixel Sensor, APS, DPS, Charge Coupled Devices, CMOS imager, pixel array, 3T APS, 4T APS, rolling shutter, global shutter, pinned-photodiode,partially pinned-photodiode, event-detection sensor, address-event representation protocol,Diagnosis of otitis media.
PhD student position in Multi-scale modelling of conductive polymer based electromechanically...
- Organization
- IMS Lab, University of Tartu
- Research Field
- Chemistry › Computational chemistry, Chemistry › Physical chemistry, Computer science › Modelling tools, Engineering › Materials engineering, Engineering › Simulation engineering, Mathematics › Algorithms, Mathematics › Applied mathematics, Physics › Computational physics, Technology › Materials technology
- Researcher Profile
- First Stage Researcher (R1)
- Deadline
- 21/02/2020 21:00 - Europe/Athens
- Location
- Estonia
- Type Of Contract
- Temporary
- Hours Per Week
- 40
- Job Status
- Full-time
- Requirements
- Languages
- ENGLISH: GoodSee the offer on Euraxess website.
Environment:
Intelligent Materials and Systems Laboratory is an interdisciplinary research group established in 2003 in University of Tartu, Institute of Technology. Our goal is, by bringing together knowledge from diverse fields of expertise, to develop new materials and their control and applications. Exploitation of innovative materials will in turn permit building devices, different and in many ways superior to conventional machines. The scientific background of our staff as well as the laboratory equipment permits research activities on the borderline of computational material science, material science, robotics, chemistry, computer science and electronics.
Project Background: Electroactive polymers (EAP) consist of materials capable of changing dimensions and/or shape in response to electrical stimuli. Most EAPs are also capable of generating electrical energy in response to applied mechanical forces. Therefore, they have potential as sensors. These polymeric materials exhibit properties well beyond what conventional metal or plastic-based actuators can offer, including very high mechanical flexibility (can be stretched to twice their initial size), low density, a high grade of processability, scalability, microfabrication readiness and, in most cases, low cost. Micro-EAPs enable a new broad range of applications for which large strains and forces are desirable, and for which built-in intelligence is necessary. One type of EAPs are ionic EAP (IEAP). They rely on ion and solvent transport to cause volume changes of the polymeric phase. When an electric field is applied to the device, it drives the motion of these ions and the entrained solvent, leading to swelling or contraction when these ions enter or leave regions of the polymer. IEAPs including Conducting Polymers (CP), present several advantages, including the capability of large bending deformation even at low (~1%) intrinsic strains of the electroactive layer; low voltages operation (0.3-5V), that make them well suited for several applications especially interfacing with biology. These materials have intrinsic capability to be also electrochemical and mechanical sensors, which also allows to design self-sensing transducers in some cases.
Objective:
The main objectives are to realize a multiscale physics model to develop model for conductive polymer based actuators based on physical and electrochemical principles. It involves to develop polarizable force filed for atom-atom interaction based simulation models (Molecular dynamics and kinetics) with further integration if output parameters into Finite element analyses computations. The final result is reasonable physics and electrochemistry based model which is enable to give predictive results for electrochemomechanical transducer behavior.
Key words: Conductive polymers, Electroactive polymer composites, Electrochemistry, Computational materials science, Ab initio, Density Functional Theory, Polarizable force field, molecular dynamics, Finite element analyze, multiscale physics
Subject Areas: computational materials science, electrochemistry, electroactive polymer materials
PhD Student position in Three-dimensional microtechnology with folding art for bio-inspired...
- Organization
- University of Tartu
- Research Field
- Computer science › Modelling tools, Engineering › Biomaterial engineering, Engineering › Design engineering, Engineering › Mechanical engineering, Engineering › Microengineering, Mathematics › Geometry
- Researcher Profile
- First Stage Researcher (R1)
- Deadline
- 20/02/2020 21:00 - Europe/Athens
- Location
- Estonia
- Type Of Contract
- Temporary
- Hours Per Week
- 40
- Job Status
- Full-time
- Requirements
- Languages
- ENGLISH: GoodSee the offer on Euraxess website.
Environment:
Intelligent Materials and Systems Laboratory is an interdisciplinary research group established in 2003 in University of Tartu, Institute of Technology. Our goal is, by bringing together knowledge from diverse fields of expertise, to develop new materials and their control and applications. Exploitation of innovative materials will in turn permit building devices, different and in many ways superior to conventional machines. The scientific background of our staff as well as the laboratory equipment permits research activities on the borderline of computational material science, material science, robotics, chemistry, computer science and electronics.
The candidate will work on mathematical modeling for folding art in silicon without affecting their performance, and in a state of the art cleanroom environment to have full access to the micro & nanofabrication platform of the IEMN laboratory (France) (https://www.iemn.fr/plates-formes/cmnf/equipements). She/He will work in close collaboration with experts from nanotechnology.
Project Background: Microtechnology has radically changed our lives, both in electronics and mechanics. For several centuries, remarkably designed vision systems have been inspired from sophisticated biological eyes. However, enormous strides can still be made in microtechnology. The current applications are two-dimensional. Everything is placed on a thin layer of glass or silicon, which is used in pure form for the production of semiconductor chips, for example, in smartphones [1]. A three-dimensional micro-eye can offer huge benefits.
Objective:
The main objectives are to realize a novel bio-inspired tunable electronic eye integrated with electronics for diagnosis of Otitis Media (OM).
The main tasks for the candidate can be divided into two axis detailed hereafter.
Task I Realizing concept of “folding art” geometry on silicon (Modeling and Simulation)
The occurrence of OM is caused due to the malfunction of Eustachian tube leading to accumulation of fluid behind the ear drum. This, in turn, causes growth of bacteria and virus. The two main complications that are misclassified by general practitioners (GPs) are Acute Otitis Media (AOM) due to bacteria and virus and Otitis Media with Effusion (OME) due to accumulation of fluid without presence of bacteria/virus. The standard diagnostic practice relies on a rigid device with large form factor namely otoscope. The existing gaps recognized are improper positioning and imaging by otoscope that leads to misclassification of OM. This leads to treatment of OM classifications (OME) that do not benefit from antibiotics, leading to development of antibiotic resistance. This stresses upon the necessity to establish a gold standard for diagnosis prior to initiating treatment.
In order to overcome the above limitations, the proposed diagnostic solution comprises a flexible microsystem with integrated contacts capable of manipulating a bio-inspired flexible silicon-based image sensor with improved auto-focus. The candidate’s task will be confined to development of the bio-inspired flexible silicon-based image sensor with improved auto-focus. By combining a simple origami approach and transfer of the design from conventional rigid technology to flexible substrate [2], the bio-inspired CMOS Image Sensor (CIS) should extend the capabilities of conventional planar systems into hemispherical systems by emulating two states namely, simple mammalian eye (concave state) in humans and compound eye (convex state) in insects, in order to have a wider view angle, lower aberrations, and infinite depth of field. This allows for unusual imaging that cannot be achieved by conventional camera systems [3].
The concept of folding rigid silicon (for instance, Origami, Kirigami etc.) is targetted to build a dense, compact, and scalable density of pixels. This concept further eliminates the use of metal wires in between pixels for interconnections. The mathematical modeling of an origami inspired approach (for instance, icosahedron, dodecahedron, rhombicosidodecahedron) could be proposed to be implemented for development of the hemispherical structure of the eye [3]. The modeling will be carried out to optimize the structure without affecting the semiconductor performance corresponding to the technology node.
Task II: Bi-stability of microcamera system with folding art (Experimental)
This activity involves thinning a standard CMOS/SOI Image sensor and transfer onto a flexible support i.e. origami deformation of the photodiode array in order to represent the bi-stable states. In order to realize the bi-stability of the camera system, the concave focal plane aray (FPA) mimiking the human eye will be reversed for mimicking the compound eye without need of external optics. In other words, artifical imaging elements are proposed to be created in order to represent the structure of compound eye, where a tiny corneal lens focuses incoming light rays onto a single photoreceptor inside (unlike mammalian eye) [5]. This maximizes the amount of light delivery incident on the photodiode, facilitating panoramic vision.
Key words: Microtechnology, Origami stucture, Rigid silicon, Geometric Modelling, Unfolding simulation, CMOS Image sensor, Diagnosis of otitis media.
References
[1] A. Legrain, J. W. Berenschot, N. R. Tas, and L. Abelmann, “Capillary origami of micro-machined micro-objects: Bi-layer conductive hinges,” Microelectron. Eng., 2015.
[2] A. Lecavelier Des Etangs-Levallois et al., “A converging route towards very high frequency, mechanically flexible, and performance stable integrated electronics,” J. Appl. Phys., 2013.
[3] K. Zhang et al., “Origami silicon optoelectronics for hemispherical electronic eye systems,” Nat. Commun., 2017.