Professional Profile

I am a system level thinker and experimental scientist and engineer; a generalist that is capable of overseeing complex interrelations and long term projects; and have a keen interest in the development of scientific instrumentation. I work systematically and organized and am a critical thinker that rarely takes things for granted. I thrive in the multidisciplinary setting of an R&D environment, where there is freedom to design future plans and visions.

Yours truly in front of the experimental setup to measure radiative heat transfer at sub-micrometer length scales. Photo by Rogier Bos and courtesy of TNO.

Academic background and work experience

Ever since I was four years old I wanted to become an astronaut. I wanted to travel across the seas of space and visit other planets. By the time I was to graduate from high school, I realized that the chances of this happening were not in my favor and I decided on the next best thing: rocket scientist.

Aerospace Engineer

From september 2008 to september 2011, I worked on a Bachelor of Science degree in Aerospace Engineering from Delft University of Technology. This was followed by a Master of Science degree in Space Systems Engineering from september 2011 to february 2014 at the same institute. During the former, I took a broad array of courses in mechanical engineering, aerodynamics, and the design of aircraft and spacecraft. After an in-depth minor in Aerospace Systems and Technology, the bachelor was concluded by a thesis on the development of a miniature telescope for use on nanosatellites. The master program provided a solid foundation in system engineering on one hand, and space-specific engineering topics such as satellite thermal control and rocket propulsion. I concluded the MSc with a thesis on the measurement of micronewton thrust levels and micronewton-second impulses from miniature rocket engines.

Doctor of Philosophy

From 2014 to now, I have been working on a Doctor of Philosophy project at the department of Structural Optimization and Mechanics, Delft University of Technology under the supervision of prof. Fred van Keulen and dr. Hamed Sadeghian of TNO. In collaboration with TNO, I developed a new scanning probe microscope that measures radiative heat transfer at sub-micrometer length scales. This technique can be used for measuring distances and thermal surface properties. I am in the final stages of the project and in the process of writing the doctoral dissertation.

Extracurricular

In 2012, Ingo Gerth, Jacco Geul, Clemens Rumpf, Weiji Wu and I founded Society Vis Viva, a professional organisation for young space engineers. Our motto — “to unite, to teach and learn, and to explore” — was threefold:

  1. offer a platform for young space engineers and scientists to gather and work together;
  2. to learn from each other and exchange ideas;
  3. and to promote the exploration of space.

As co-founder and chairman (2012 – 2016), I was (co)responsible for the day-to-day operation of the society, developing and carrying out its philosophy and lead the bi-weekly meetings. 

From 2011 to 2012, I provided private tutoring for several students that were at the end of their bachelor of science degrees. The course material consisted of calculus, linear algebra, differential equations, numerical modeling and programming in Mathworks Matlab and Java. Rather than focusing on the current material, I focused on making sure that the fundamentels were well understood and mastered, so that the students could grasp the more complex problems themselves. 

Professional portfolio

Measurement of Radiative Heat Transfer at Sub-micrometer Length Scales (4+ years)

At sub-micrometer length scales, radiative heat transfer can no longer be described accurately using the Stefan-Boltzmann law and becomes highly dependent on distance. My interest is in measuring this distance-dependent heat transfer and using it for distance measurement and for contactless scanning probe microscopy. Over the course of more than four years, I have taken this idea from concept to realization. I improved the systems architecture such that the measurement no longer requires calibration of the probe, and can be made traceable to international standards. I designed and implemented a table-top optical beam deflection system with feedback on the laser output for the heat transfer measurement, an integrated confocal microscope for alignment purposes, a total internal reflection microscope for measuring the distance between probe and sample, two thermal control systems with millikelvin stability and an ultra-high vacuum facility.

In addition to the proof-of-principle setup, this research has resulted in two patents, three conference papers, and several journal publications that are pending review and/or publication.

Close up of the vacuum part of the setup. Photo by Rogier Bos and courtesy of TNO.

Design, Verification and Validation of a Micropropulsion Thrust Stand (1 year)

At the chair of Space Systems Engineering of Delft University of Technology, students and staff work on the development of small rocket propulsion systems for the use on satellites for station keeping, attitude control and orbit maneuvers. This requires new designs that need to be tested and qualified. I redesigned an existing test stand to extend its range from 0.5 mN – 2 mN to 1 µN – 5 mN and introduced the capability to also measure impulse bits. In addition to this, I developed a traceable calibration method that could be performed in situ and can be used for closed loop operation. Paramount in this was the design of an electromagnetic actuator with variable turn density in its coil, which is designed such that the applied force on a permanent magnet is independent of the axial position of the magnet.  The setup was validated by measuring the thrust of a previously tested rocket engine provided by Bradford Engineering. This work has been presented at the Space Propulsion 2014 conference in Cologne. The setup has since been used in the testing of small rocket engines as part of several MSc and PhD projects.

Front and side view of the developed pendulum used to measure the thrust and impulse bits generated by a microthruster. Photo by Roy Bijster.

Development of Calibration Methods of AFM Probes (3 months)

In Atomic Force Microscopy (AFM) a small cantilever beam with a sharp tip is scanned over a sample surface to record its topography and surface properties. For quantified measurements, the stiffness of this cantilever is an important parameter that needs to be calibrated. Available techniques require destructive experiments or provide low accuracy. I developed a new method that can be performed without the need for destructive experiments and relies on measuring the static and dynamic thermal properties of the probe. This can be done using the readout optics used in commercial systems and only requires that the output power of the laser can be modulated. I performed the theoretical modelling for this technique, and performed validation measurements on a table-top AFM system. The technique proved also useful for the quick alignment of the laser on the probe tip. This research resulted in amendments in a patent application, a conference paper and a publication in Applied Physics Letters.

Conceptual Design and Systems Engineering for a High Bandwidth MEMS Actuator (4 months)

A linear MEMS actuator is used as the last actuator in the three-tier design of a mechatronic platform for near-field imaging microscopy. Such a microscope requires that a flat lens is positioned roughly 20 nm away from the sample surface and can be positioned with sub-nanometer accuracy and with high speed to meet industry requirements. I was involved with the design of this MEMS stage in an early stadium, and was responsible for the system architecture and conceptual design. That entailed, amongst others, a theoretical analysis of the high level requirements and their implications for the system design, a study of the material-sample interaction at such small distances and corresponding technical risks and the development of an architecture that mitigated these risks.

Micrograph of the realized device.