Professor and lecturer at HE-Arc Engineering

Born in 1976

Lives in Lausanne

Alexandra Homsy was born in Annemasse (France). She studied engineering physics at EPF in Lausanne in 1999 and obtained a Doctor of Sciences from the University of Neuchâtel in 2006. She first discovered the world of microtechnology towards the end of her studies in physics. She noticed that it was possible to save lives by miniaturising medical diagnosis systems. While completing her post-doc in Ireland, where the manufacturing systems were very limited compared to the equipment at Professor Nico de Rooij’s laboratory, she realised that a very sophisticated clean room was not necessary to develop microsystems. Back in Neuchâtel in Switzerland, she began to work on the industrialisation of medical diagnosis microsystems with Prof. De Rooij. It was at this point that she realised the need to develop microchips for the preparation of “real” samples such as blood or saliva.
She is currently a professor and lecturer at HE-Arc Ingénierie. She devotes half of her time to teaching micro- and nanotechnology and their applications in medical engineering. The rest of her time is spent in the Medical Devices laboratory on the Neode premises in La Chaux-de-Fonds working on her research projects. She works in particular with Sébastien Brun, CEO of start-up SY&SE.

Today, many medical diagnoses are based on analysing biological samples. How is your research helping to improve sampling processes ?

When taking a sample, such as a drop of blood, many different handling stages are involved. These operations require particular protocols and special training and are subject to many potential mishaps.

By using microsystems or “microchip laboratories” we hope to improve:

  • portability, as the sample can be analysed anywhere;
  • stages such as pumping the liquid, detection and preparation of the sample can be simplified and automated;
  • speed, as the steps are automated, saving a considerable amount of time;
  • reliability, reducing the risk of error by reducing human intervention.

These microsystems can either filter a single drop of blood, or be connected to a drip system that filters the blood continuously. The ultimate aim of my research is to help develop a microchip laboratory with completely integrated instruments.

What are the major challenges involved in the analysis of blood samples ?

I can see two main challenges. First of all, blood composition varies from one person to another. The components of the blood are the same, but their quantity varies, which puts the reliability of the analysis to the test. The challenge lies in proving that the analysis results obtained during a clinical study are similar, despite diversity in blood samples. We work with doctors from university hospitals because:

  • We can make products that best meet their expectations ;
  • They have access to samples to test the reliability of the system developed ;
  • They have funding to test the new concept..

Doctors are showing increasing interest in microsystems !
Second, each microchip laboratory depends on the final application. In my developments, only the architecture of my microchannels (design, size, positioning of the structures, material, wettability of the surfaces) influences the system’s operation. So every project gives rise to a different chip with a different material and design. Unfortunately, there is no ready-made solution.

Why are you passionate about this field and what is your ultimate goal ?

I am fascinated by the multidisciplinarity of this field. I work with chemists (interactions between molecules and surfaces and between molecules themselves), physicists (optical measurements of the biomarkers that emit photons), biologists and doctors (practical needs in the field), and engineers (instruments). Furthermore, as the field of microfluidics only developed around twenty years ago, you have to be able to make yourself understood and communicate effectively about the topic. Lastly, knowing that you could improve the life of patients is also a great source of motivation.
I hope that these microchips will one day be connected to smartphones, for instance, to enable real-time diagnoses. This would be very useful in crisis situations or in locations without laboratory infrastructures.

With the Drugsense project, you helped to integrate a biosensor able to measure the presence of a chemotherapeutic agent in the blood. How does this sensor work and why does it improve the patient’s care during treatment ?

During chemotherapy, the treatment is administered over 24 to 48 hours. The aim is to kill cancerous cells before healthy cells. With this HES-SO project, we made it possible to continuously measure the presence of this agent in the blood plasma. The dosage could therefore be adjusted in real time. The therapy could then be personalised and optimised for each patient.

Why did you choose to carry out your research in the Neuchâtel region ?

I had my first experience working as a researcher in Neuchâtel, at Nico de Rooij’s laboratory. But I am equally passionate about teaching and applied research. So I naturally approached HE-Arc Ingénierie to carry out my research. I also work with CSEM and the Neuchâtel branch of EPFL, which offer complementary skills. We all benefit from the existing innovation ecosystem, particularly in microtechnology.

Written by Victoria Barras

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