I came to the OU after 20 years working as an engineer in industry, most recently in the field of micro-electromechanical systems. This is a manufacturing technology that uses wafer-scale processing techniques to shape materials such as silicon and glass into miniature physically or chemically active components. This has largely involved designing sensors of various kinds (accelerometers, pressure sensors, CO2 sensors), as well as structures such as microfluidic devices and integrated optical chips. An important process within this technology is that of semiconductor wafer to wafer bonding, and since joining the OU I have been trying to understand the mechanisms by which exposing wafers to gas discharges enhances the strength of the bond made subsequently.
More recently, I have been working on the measurement of residual stress. Here, we have been improving a relatively new method of mapping residual stresses, known as the contour method, in which the sample to be measured is first carefully cut in two using a wire electrodischarge machine. The deviations from flatness of the cut surfaces are then measured and these data are used in a finite element model to calculate the residual stresses that must have been present before the cut was made.
I am the Director of Teaching for the School of Engineering and Innovation.
I am a module team member on T176, T276, T207, T356, T802 and T885 and critical reader for the new Stage 2 core engineering module currently in production, T271.
|Atomic, Molecular and Optical Research Group||Group||Faculty of Science|
|Materials Engineering Group||Group||Faculty of Mathematics, Computing and Technology|
Efficient hole transport material formed by atmospheric pressure plasma functionalization of Spiro-OMeTAD (2020-09)
Ghosh, Paheli; Ivaturi, Aruna; Bhattacharya, Debabrata; Bowen, James; Nixon, Tony; Kowal, Jan; Braithwaite, Nicholas St John and Krishnamurthy, Satheesh
Materials Today Chemistry, 17, Article 100321
Determination of normal and shear residual stresses from fracture surface mismatch (2015-10-15)
Araujo de Oliveira, J.; Kowal, J.; Gungor, S. and Fitzpatrick, M. E.
Materials & Design, 83(C) (pp. 176-184)
Towards good practice guidelines for the contour method of residual stress measurement (2014-08-27)
Hosseinzadeh, Foroogh; Kowal, Jan and Bouchard, Peter John
Journal of Engineering ((Online only))
A review of hydrophilic silicon wafer bonding (2014-02-03)
Masteika, V.; Kowal, J.; Braithwaite, N. St.J. and Rogers, T.
ECS Journal of Solid State Science and Technology, 3(4) (Q42-Q54)
The effect of atmospheric moisture on crack propagation in the interface between directly bonded silicon wafers (2013-05)
Masteika, V.; Kowal, J.; Braithwaite, N St.J and Rogers, T.
Microsystem Technologies, 19(5) (pp. 705-712)
Surface activation for low temperature wafer fusion bonding by radicals produced in an oxygen discharge (2009-10)
Kowal, J.; Nixon, T.; Aitken, N. and Braithwaite, N. St. J.
Sensors and Actuators A: Physical, 155(1) (pp. 145-151)
Selection of glass, anodic bonding conditions and material compatibility for silicon-glass capacitive sensors (1995-01)
Rogers, T. and Kowal, J.
Sensors and Actuators A: Physical, 46(1-3) (pp. 113-120)
Residual stress measurements on a metal matrix composite using the contour method with brittle fracture (2014-08-11)
Araujo de Oliveira, Jeferson; Fitzpatrick, Michael E. and Kowal, Jan
In : 9th European Conference on Residual Stresses (7-10 Jul 2014, Troyes, France) (pp. 349-354)
Residual stress measurement in a stainless steel clad ferritic plate using the contour method (2013)
Naveed, Nida; Hosseinzadeh, Foroogh and Kowal, Jan
In : ASME 2013 Pressure Vessels and Piping Conference (14-18 Jul 2013)
The philosophy and pedagogy of practical work for engineering undergraduates and the potential for online practical activities to enhance their experience - An exploratory workshop (2012-09-20)
Endean, Mark; Goodyear, Alec; James, Jon; Kowal, Jan and Williams, Keith
In : EE 2012 - International Conference on Innovation, Practice and Research in Engineering Education, Conference Proceedings (18-20 Sep 2012, Coventry University)
An electrostatic actuated micro-structure for high-cycle fatigue testing (2005)
Polido Gomes, J.; Kowal, J. and Edwards, L.
In : Proceedings of the 2005 SEM Annual Conference and Exposition on Experimental and Applied Mechanics (7-9 Jun 2005, Portland, Oregon, USA)
Surface activation and direct bonding of semiconductor wafers (2009-09-16)
Braithwaite, Nick; Al-Kuzee, Jafar; Lima, Paulo and Kowal, Jan
Timing arrangement for an air flow meter (1997-10-01)