Projects

Ionic Polymer Metal Composites (IPMC) modelling and control

This research focuses on building EAP devices as well as methods for their control. Particularly, we are focusing at the following research problems:

• Electromechanical modelling of IPMC materials
• Design of novel IPMC actuators.
• Development of position sensors for IPMC actuators.
• Development of control methods of IPMC actuators to achieve less energy consumption at large output force and torque.
• Development of feedback control methods for IPMC actuators.
• Design of autonomous IPMC actuators and devices.

Carbon-Polymer Composite Electroactive Materials

This research focuse on developing new materials based on carbide derived carbon, polymer matrix and ioni liquid composite materials. These materials are relatively strong and well controllable by open loop current control. It is possible to prepare either bending or expanding(linear) actuators. Particularly, we are focusing on:

• Design of material with specific electromechanical properties (speed, force)
• Atomistic and electromechanical modelling of the material
• Design of the actuators suitable for Lab-on-Chip applications
• Development of the fabrication technology suitable for LoC applications
• Design of prototypes for several applications

Radiation and temperature induced damage of ionic electroactive polymer materials for MEMS devices in space

The mission of the proposal is to develop reliable actuators for MEMS devices in space craft. The reliability (or perceived lack thereof) of MEMS devices, rather than their actual performance, is limiting the acceptance of MEMS in spacecraft, despite their intrinsic appeal in view of their low mass, low power consumption, small volume, low vibration and simple kinematics and possible integration with control and sense electronics. Polymeric MEMS sensors and actuators are extremely appealing for reducing the size and mass of spacecraft without sacrificing functionality. In view of the harsh and remote environment of space, reliability and qualification is the crucial issues that are holding back MEMS from playing a larger role in space applications. Using smart microdevices will reduce cost of the mission. MEMS have been commercially adopted in large volumes in a number of earth‐bound applications, the most common being the safety critical accelerometers for automotive (airbag) applications, pressure sensors for engine management, and micro‐mirror arrays for display applications. There is a high level of interest in adapting MEMS from Earth application for Space, or developing MEMS for specific space applications. In all cases, radiation tolerance is a critical aspect. Major Objectives

• To study effects of extreme space conditions to Carbon-(polymer)-ionic-liquid(CIL) electroactive polymer (EAP) materials.
• To develop design techniques and packaging approaches to make CIL-EAP MEMS devices much less sensitive to trapped charge, ionization effects and temperature by geometry, materials, and control scheme improvements.
• To develop reliable testing and validation routine of ionic EAP materials for devices in spacecraft.

Multiscale Modelling and Materials by Design of interface-controlled Radiation Damage in Crystalline Materials (RADINTERFACE)

Radiation damage is known to lead to materials failure and thus is of critical importance to lifetime and safety within nuclear reactors. While materials mechanical behavior under irradiation has been subject to numerous studies, the current predictive capabilities appear limited. Observations and physical models have shown that the most important damage contributions arise from point defect localization –leading to void swelling- and creep. It was recently found that void swelling can be prevented via use of non coherent heterophase interfaces. It is very likely that other interface types may exhibit similar trends. Unfortunately, no tool is available to generally predict the effect of interface composition (monophase, heterophase) and structure (geometry, roughness) on its propensity to resist radiation damage (both via defect localization and creep). These limitations motivate the proposed study which aims at developing such tool. Given the multi-scale multi physics nature of the problem, the consortium is formed by experts in the fields of materials modeling via ab initio, molecular dynamics and continuum modeling as well as of materials characterization and processing via mechanical alloying and physical vapor deposition.

The program aims at constructing a bottom-up framework allowing discovery and quantifications of materials damage mechanisms and effects on mechanical properties for novel crystalline materials with large interfacial areas. Model validation will arise through direct comparison with materials testing for a wide array of materials systems (metal/metal, metal/oxide, oxide/oxide).

The main tasks of IMS lab are quantum chemical calculations and the development of forcefield for the Molecular Dynamics (MD.

Partners: Centre National de la Recherche Scientifique, University of Oviedo, Universidad Politecnica de Madrid, Ecole des Mines de Paris-ARMINES, Czech Technical University in Prague, Universita degli Studi di Cagliari, University of Tartu, Uppsala University, IMDEA Materials Institute, Los Alamos National Laboratory.

Funding Organisation: NMP, 7th Framework Programme Region: Europe Project Period: 2011-2013

Material study of conducting polymers

Electronically conducting polymers, polypyrrole (PPy) in particular, have been under heavy investigation during the last decades. Their useful optical, conductive, ion-exchange properties have already found use at the industrial level in various capacitors, displays, sensors, analyzers, etc. In addition to the practical use of these “classical” properties, several promising applications of the conducting polymers have been proposed in recent years, employing the bio-compatibility or electromechanical features of these polymers. Unfortunately, the lack of fundamental atomistic understanding of the development of the properties of the conducting polymers is hindering the wider use of the novel applications proposed. Our main focus has been the establishment of the relationships between the synthesis conditions, the structure and the properties of the polymers. Another field of interest is the stability (both chemical and physical) of these materials (especially if used in air, aqueous solutions or bio-liquids). Electrochemistry, spectroscopy, electron- and probe microscopy as well as theoretical modeling have been employed in order to gain a better understanding of these issues.

Molecular dynamics studies of poly(ethylene oxide) based electrolytes

Solid electrolytes for the Lithium-Ion Polymer Battery can be produced by mixing a lithium salt, typically LiPF₆ or LiBF₄, into poly(ethylene oxide) (PEO), -(CH₂CH₂O)n-. However, such electrolytes only exhibit adequate ionic conductivity (>10^-4 S/cm) at temperatures above 70°C, where the polymer becomes amorphous. The conventional wisdom has been that the high degree of local order (“crystallinity”) is the reason for the poor ionic conductivity at ambient temperatures. Much attention has therefore been devoted to the task of increasing the amorphous content of the PEO electrolyte at ambient temperatures.

Computer-Aided Materials Design for Proton-Conducting Fluoropolymers

Molecular Dynamics (MD) simulations give us a chance to have close insights into Nafion's dynamics and local structure on molecular level. We can study the details of proton-conductivity and find out the mechanisms what can possibly improve this process. We are interested in following research problems:

• design of the realistic and reliable Molecular Dynamics simulation model for Nafion as an electrolyte in the fuel cell,
• simulations of proton hopping mechanism between Nafion chain and surrounding water,
• the effects of Nafion side chains on the proton dynamics.

ICT DCNet

Latvia (LV) and Estonia (EE) have been doing local ICT mechanic(robotics) activities for last few years. But all initiatives are planned and implemented inside one country. Some activities have been done on contest basis for many countries, but the continuity of the activities did not take place. In order to reduce national isolation and to foster external connectivity in a high value added innovative field of ICT mechanics, a joint project idea was developed. Project idea focuses on reducing external isolation by developing a joint Demo Centre [DC] network of exhibiting ICT mechanics solutions to foster information flow, by harmonising ICT study module, and by joint cross-border contests, thus to develop ICT network and improve overall access to ICT services through cross-border networking, cooperation and common information space. DC-s will be established on a joint ICT mechanics basis with each DC covering specific ICT niche. LV DC-s will cover satellite ICT DC and ICT mechanics (robotics) software DC. Tartu DC will cover ICT Mobile and location based services applications. Further activities are developed so to have a continuous joint character, by developing basic cross-border cooperation through study process, further involving DC that will work as prototype solutions exhibition places and finally getting together people interested in ICT mechanics, starting from school children, students, all enthusiasts, through joint contests. Thus a cycle of subactivities are planned to foster one joint aim of improving overall connectivity and access to information flow of innovative ICT solutions. Continuity of the program activities is ensured by developing basis for ICT mechanics further development and involving all stakeholders and interested parties. As a result cohesion of program area is increased and international competitiveness of program area is fostered.

Self-deployable Habitat for Extreme Environments

The main objective of the SHEE project is the exploration of an effective integration of architecture and robotics for space applications. The goal is to develop a robotically-deployable habitat design introducing generic principles which would help in defining main themes for further development of the standards for robotics integrated into the architecture regarding safety and for the development and design of larger robotic structures. Self-deployable autonomous habitats are needed in particular in extreme environments without infrastructure and heavy machinery. Such habitats will mitigate construction safety risks and reduce costs. The SHEE type of habitat will provide significant background for further development and evolution of extra-terrestrial habitable structures and will provide a methodology and results that can be translated into more “normal” conditions and to achieving a more efficient, high-tech sector on earth.

Multiscale simulations of materials in high electric fields

The Compact Linear Collider (CLIC) is a new accelerator, developed in CERN, utilizing electron-positron beam collisions to reach energies from 0.5 TeV to 5 TeV. To achieve this kind of energies, very high accelerating gradients, reaching over 100 MV/m, are needed. However, in such kind of high electrical field one of the key problems, arising during the operations are the repeated electrical breakdowns in the accelerating structures. The electrical breakdowns are caused by the vacuum arching, but currently, the exact mechanism leading to vacuum arching is not known. Generally, it is assumed, that the vacuum arch is triggered by nanoscale field emitters (needle-like structures), appearing on the surface of the accelerating structures. In current work, different computational methods, like Molecular Dynamics and Finite Element Method are utilized to identify the physical phenomena leading to the growth of these field emitting tips. The work is conducted in collaboration with Helsinki University and CERN. Current activities include:

• Molecular Dynamics simulations of FCC metals
• Elastoplastic deformations of coupled electric field and metal interactions
• Emission currents and material heating due to high el. fields
• Atomistic surface reconstruction