Wojciech Dera, M.Sc., Eng.

Department of Theory of Continuous Media and Nanostructures (ZTOCiN)
Division of Polymer Physics (PFP)
position: specialist
telephone: (+48) 22 826 12 81 ext.: 107
room: 237
e-mail: wdera

Recent publications
1.Jarząbek D.M., Dziekoński C., Dera W., Chrzanowska J., Wojciechowski T., Influence of Cu coating of SiC particles on mechanical properties of Ni/SiC co-electrodeposited composites, CERAMICS INTERNATIONAL, ISSN: 0272-8842, DOI: 10.1016/j.ceramint.2018.08.271, Vol.44, pp.21750-21758, 2018
Abstract:

In this paper, the study of the mechanical properties of composites consisting of electrodeposited Ni and co-electrodeposited SiC particles coated with a thin Cu layer was presented. It was demonstrated that the coating allowed to increase the concentration of ceramic particles in the composite. Although the plating parameters were the same for both types of composites, the concentration of SiC was 15% for the composite containing coated particles (Ni/SiC-Cu) and 10% for the composite containing uncoated particles (Ni/SiC). Furthermore, tensile tests showed that the Ni/SiC-Cu samples exhibited higher Young's modulus than the pure electrodeposited Ni samples or Ni/SiC samples. The measured Young's modulus of the Ni/SiC-Cu composite was 250 ± 10 GPa. However, the ultimate tensile strength of the Ni/SiC-Cu composite was lower than that of pure Ni. To explain the mechanical behaviour of the Ni/SiC-Cu composite, the microstructure of the interface of this composite and its bonding strength were studied. Microstructure studies conducted using a scanning electron microscope (SEM) revealed that the SiC/Cu interface was smooth and of good quality whereas the Cu/Ni interface was rough but also of good quality. The measured bonding, normal, and shear strength values demonstrated that the SiC/Cu interface was weak, and that was the main reason for the low ultimate tensile strength of the composite. The shear strength of the SiC/Cu interface was measured using a novel method: micropillars shearing including atomic force microscopy (AFM). Finally, a simple finite element model of the Ni/SiC-Cu composite, based on cohesive elements, was developed.

Keywords:

Interfacial bonding strength, Metal matrix composites, Tensile strength, Silicon carbide, Electrodeposited nickel

Affiliations:
Jarząbek D.M.-IPPT PAN
Dziekoński C.-IPPT PAN
Dera W.-IPPT PAN
Chrzanowska J.-IPPT PAN
Wojciechowski T.-Institute of Physics, Polish Academy of Sciences (PL)
2.Jarząbek D.M., Gwiazda M., Dera W., The Influence of Alkali Metal Chloride Treatments on the Wear Resistance of Silicon Surfaces for Possible Use in MEMS, TRIBOLOGY TRANSACTIONS, ISSN: 1040-2004, DOI: 10.1080/10402004.2017.1296211, Vol.61, No.1, pp.178-184, 2018
Abstract:

The wear of contacting silicon surfaces in microelectromechanical systems (MEMS) has been a longstanding concern. To address this issue, the effects of immersing silicon surfaces into alkali metal chloride solutions (LiCl, NaCl, CsCl) on their sliding friction and wear were investigated. A custom-built reciprocating tribometer was used with a sapphire ball as the counterbody. Results indicated that the friction coefficient between the silicon surface (p-doped, orientation (100)) and a sapphire ball can be reduced by up to 30% by treating the silicon surfaces in aqueous salt solutions (concentration 1 mol/L, exposure for 24 h). These modified surfaces also have higher wear resistance and a significant change in wettability. After immersion, the contact angle between the silicon surface and water was reduced by approximately 50%. These results may lead to new, simple, and inexpensive methods to increase the wear resistance of silicon surfaces for use in MEMs devices.

Keywords:

silicon surface, wear, friction, alkali metal chlorides

Affiliations:
Jarząbek D.M.-IPPT PAN
Gwiazda M.-Warsaw University of Technology (PL)
Dera W.-IPPT PAN
3.Frąś L.J., Dziekoński C., Dera W., Jarząbek D.M., Piezoelectric bimorph as a high-sensitivity viscosity resonant sensor to test the anisotropy of magnetorheological fluid, REVIEW OF SCIENTIFIC INSTRUMENTS, ISSN: 0034-6748, DOI: 10.1063/1.5025123, Vol.89, No.10, pp.105111-1-7, 2018
Abstract:

In this paper, we present a device which is very sensitive for small changes in the viscosity of the investigated fluid. The main part of the device is a piezo-electric bimorph which consists of the brass shim with two piezo-ceramic layers on the opposite sides. One of them is responsible for generating vibrations, whereas the second one is meant to measure system response which is produced by the damping properties of the surrounding fluid. During the experiment, the cylindrical bar is forced to move by the series of sinusoidal waves with different frequencies and at constant amplitudes. The probe is immersed in the fluid and then the amplitude vs frequency and phase vs frequency curves are obtained. Next, one can determine the viscosity according to a proper mathematical model. The resonant frequency is related to the damping coefficient which depends on the viscosity of the surrender fluid and immersion depth of the probe. The coefficients necessary for calculating viscosity are obtained by fitting the resonance curve to the amplitude vs frequency data obtained from the experiment. The device has been applied to study the anisotropy of magnetorheological fluids. The weak anisotropy of viscosity has been observed. The highest value of viscosity was observed in the case of viscosity measurement in the direction orthogonal to the magnetic field and the lowest in the direction parallel to the magnetic field.

Affiliations:
Frąś L.J.-IPPT PAN
Dziekoński C.-IPPT PAN
Dera W.-IPPT PAN
Jarząbek D.M.-IPPT PAN
4.Dziekoński C., Dera W., Jarząbek D.M., Method for lateral force calibration in atomic force microscope using MEMS microforce sensor, ULTRAMICROSCOPY, ISSN: 0304-3991, DOI: 10.1016/j.ultramic.2017.06.012, Vol.182, pp.1-9, 2017
Abstract:

In this paper we present a simple and direct method for the lateral force calibration constant determination. Our procedure does not require any knowledge about material or geometrical parameters of an investigated cantilever. We apply a commercially available microforce sensor with advanced electronics for direct measurement of the friction force applied by the cantilever's tip to a flat surface of the microforce sensor measuring beam. Due to the third law of dynamics, the friction force of the equal value tilts the AFM cantilever. Therefore, torsional (lateral force) signal is compared with the signal from the microforce sensor and the lateral force calibration constant is determined. The method is easy to perform and could be widely used for the lateral force calibration constant determination in many types of atomic force microscopes.

Keywords:

A precise and direct method for lateral force calibration, Inaccuracy equal to approximately 2%, Wedge method is proven to give inaccurate results

Affiliations:
Dziekoński C.-IPPT PAN
Dera W.-IPPT PAN
Jarząbek D.M.-IPPT PAN
5.Kujawska T., Dera W., Dziekoński C., Automated bimodal ultrasound device for preclinical testing of HIFU technique in treatment of solid tumors implanted into small animals , HYDROACOUSTICS, ISSN: 1642-1817, Vol.20, pp.93-98, 2017
Abstract:

In Poland cancer is the second cause of death overall, and the first before 65. Demand for new anticancer therapies is increasing every year. The main objective of studies on medical and technical aspects of new anticancer methods is to reduce unwanted side effects and costs associated with conventional methods of treatment. Percutaneous (noninvasive) HIFU (High Intensity Focused Ultrasound) technique gives the chance to radically reduce both of these factors. The main goal of this work is automation of HIFU technology for producing thermal damage to the entire volume of a solid breast tumor implanted into a rat mammary gland using the proposed bi-modal ultrasound equipment, enabling the ultrasonic heating of a small volume within the tumor under the ultrasonic imaging control, as well as 3D scanning of the heating beam focus throughout the entire tumor volume. Design of the proposed equipment includes the heating probe of low frequency (about 1MHz), allowing penetration of pulsed focused waves into tissues, and the linear phased array probe of high frequency (from 4 MHz to 10 MHz), allowing visualization of the locally heated area inside the tumor in real time. Automatic 3D scanning of the heating beam focus provides the thermal damage to its entire volume.

Keywords:

High Intensity Focused Ultrasound beam, focal volume, tissue damage

Affiliations:
Kujawska T.-IPPT PAN
Dera W.-IPPT PAN
Dziekoński C.-IPPT PAN

List of chapters in recent monographs
1.
509
Jarząbek D.M., Dera W., Ceramic Matrix Materials - Materials, Manufacturing and Engineering, Series: Advanced Composites, rozdział: The measurement of mechanical properties of interfaces in ceramic composites, Walter de Gruyter GmbH, Berlin/Boston, Printed in Germany, 5, pp.77-108, 2016

Conference abstracts
1.Dera W., Dziekoński C., Jarząbek D.M., Method for lateral force calibration in atomic force microscope using MEMS microforce sensor, 8TH International Colloquium Micro-Tribology, 2017-09-11/09-13, Warszawa (PL), pp.1, 2017
2.Frąś L.J., Dziekoński C., Dera W., Jarząbek D.M., The anisotrophy of viscosity of magnetorheological fluid., 8TH International Colloquium Micro-Tribology, 2017-09-11/09-13, Warszawa (PL), pp.1, 2017
3.Dera W., Dziekoński C., Jarząbek D.M., Lateral force calibration in atomic force microscope using MEMS microforce sensor, EUROMAT 2017 , European Congress and Exhibition on Advanced Materials and Processes, 2017-09-17/09-22, Thessaloniki (GR), pp.1, 2017
4.Dziekoński C., Jarząbek D.M., Dera W., Influence of mode of electrodeposition, grain size on mechanical propertice of electrodeposited nanocrystaline nickel coatings., EUROMAT 2017 , European Congress and Exhibition on Advanced Materials and Processes, 2017-09-17/09-22, Thessaloniki (GR), pp.38, 2017
5.Dziekoński C., Dera W., Frąś L., Jarząbek D.M., Precise force sensors for micro and nanotensile tests., SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), pp.1, 2016
6.Dera W., Dziekoński C., Jarząbek D.M., The measurement of viscosity of thin polymer films, SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), pp.1, 2016
7.Jarząbek D.M., Dera W., Rymuza Z., The measurement of viscosity of ultrathin polymer films, EUROMAT 2015, European Congress and Exhibition on Advanced Materials and Processes, 2015-09-20/09-24, Warszawa (PL), pp.1, 2015
Abstract:

Viscosity is a very important property of thin polymer films used in modern microelectronic technology i.e. in nanoimprint lithography. Hence, in this work we present a method for viscosity of ultrathin polymer films determination. The viscosity is evaluated from the response of the oscillating piezoelectric cantilever at the end of which an indentation probe is mounted (Fig. 1a). When a polymer film is indented, the resonant frequency of the oscillations is changed and the parameters of used model (i.e. Maxwell model) can be identified. The frequency of the oscillations is equal to tens of kilohertz therefore the influence of extremely high deformation velocities can be investigated by means of this method. It is also possible to conduct the experiments in elevated temperature (up to 150 o C). The oscillations direction can be parallel as well as perpendicular to the fil m’s surface. The investigated films were made of PMMA. Their thickness ranges from a few nanometers up to 1 micrometer. The results were compared with other methods of the viscosity determination: the investigation of the creep response during nanoindentation, sinus mode nanoindentation and atomic force microscope based technique

Affiliations:
Jarząbek D.M.-IPPT PAN
Dera W.-IPPT PAN
Rymuza Z.-other affiliation
8.Jarząbek D.M., Dera W., Rymuza Z., The measurement of viscosity of ultrathin polymer films, Nanomechanical Testing in Materials Research and Development V, 2015-10-04/10-09, Albufeira (PT), pp.1, 2015

Patents
Numer/data zgłoszenia patentowego
Ogłoszenie o zgłoszeniu patentowym
Twórca / twórcy
Tytuł
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Ogłoszenie o udzieleniu patentu
pdf
17460072.6
2017-12-04
EP3361266
2018-08-15
Jarząbek D., Dera W., Dziekoński C.
Method of lateral force calibration in an AFM microscope and device for lateral force calibration in an AFM microscope
AL, AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GB, GR, HR, HU, IE, IS, IT, LI, LT, LU, LV, MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK, SM, TR, Instytut Podstawowych Problemów Techniki Polskiej Akademii Nauk
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422789
2017-09-08
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Kujawska T., Dera W., Dziekoński C.
Bimodalne urządzenie ultradźwiękowe do nieinwazyjnego niszczenia litych guzów nowotworowych u małych zwierząt
PL, Instytut Podstawowych Problemów Techniki PAN
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419669
2016-12-02
BUP 12/18
2018-06-04
Dera W., Dziekoński C., Jarząbek D.
Metoda kalibracji siły bocznej w mikroskopie AFM i urządzenie do kalibracji siły bocznej w mikroskopie AFM.
PL, Instytut Podstawowych Problemów Techniki PAN
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419571
2016-11-23
BUP 12/18
2018-06-04
Jarząbek D., Dera W., Dziekoński C.
Urządzenie do pomiaru lepkości cienkich warstw materiałów lepkosprężystych
PL, Instytut Podstawowych Problemów Techniki PAN
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