The value of Master’s students and serendipity for hDMT research

A true story (by Ronald Dekker TU Delft/Philips)

Serendipity, or the discovery of something interesting or useful while working on something completely different, is an important aspect in the life of any researcher. A typical case of serendipity led to a spontaneous and above all fun project between TUDelft, TU/e and Philips Research in which a handful of master students played a leading role.

The serendipity moment

While working on an integration technology for smart catheters, we needed to develop a method to make channels in a silicon wafer that were closed from the top. Together with some students a simple technology trick was developed that worked like a dream. Looking at electron-microscope pictures of these channels, we realized that they also could be used to make “embedded” microfluidic structures in a silicon chip!  Silicon is not the most obvious material for microfluidics. Most microfluidic devices are made in glass or a polymer like PDMS. Silicon is usually being considered to be too expensive. However, silicon does have a number of advantages: it is possible to integrate sensors and electronics, and above all, there is a huge industrial base for manufacturing it.

The collaboration

Micro-fluidics is the specialism of Jaap den Toonder at the TU/e, and since he lives “around the corner” in Eindhoven we sat around the table to see if we could do something useful with the technology. As it happened he had a PhD student who had just finished her research project on a device that tests the effect of drugs on cells by measuring the stiffness of cells before and after exposing them to the drug. The stiffness is measured by timing how long it takes to squeeze the cells through a restriction channel.  Her device was made from polymers, and we decided to make a similar device in silicon.

The Master’s students

Shiva Dahar, a master’s student from biomedical engineering in Delft came to Eindhoven to design and make the first devices in our cleanroom at Philips. She developed a very simple process to make the devices. The fabrication is so simple that the complete device can be made in a few days.

Rene Henderikx, a master student from Jaap den Toonder at TU/e tested the device with cells. He soon discovered some flaws in the first design, and together with James Muganda, a Delft master student, a second design was fabricated.

In the meantime Shinnosuke Kawasaki in Delft has started his master project with the goal to equip the chip with sensors and electronics to measure the velocity of the cells electrically instead of optically. He will integrate electrodes and use a cheap 200 euro “red pitaya” development board to detect the velocity of the cells using impedance spectroscopy.

The Result

In short, a truly multidisciplinary Organ-on-Chip project that demonstrates that even on a low budget, with a group of enthusiastic master students interesting and valuable research projects can be executed in line with the true spirit of the hDMT institute.

Shiva Dahar (TU Delft), James Muganda (TU Delft), Shinnosuke Kawasaki (TU Delft) and Rene Henderikx (TU/e)