Are you ready to work on the old dream of injecting without needles and to contribute to a world with less contamination caused by medical treatments and cosmetic procedures?

We offer an exciting Postdoc position in the Mesoscale Chemical Systems group.

Join our highly motivated and multidisciplinary team working on revolutionary methods for needle-free injections!

Injecting without needles is challenging because all skins are different. The study of fast traveling tiny droplets impacting on soft substrates will give you and our highly motivated team the knowledge to inject without harming the skin. It will also enable the determination of skin properties for vaccinations, cosmetics, and other uses, where needles are feared.

This project will use state-of-the-art technology developed in the BuBble Gun Project ( Together with collaborating experts from medical centers, commercial partners and spin-off companies, this project will contribute to developing a novel technology to provide personalized and effective medical and cosmetic treatments.

As part of the NWO funded VIDI project, we are looking to fill two PhD positions (4 years), and one post-doc position (1.5 years). For an example of recent work done in this line of research, please check:

·       Cu, Delivery Strategies for Skin: Comparison of Nanoliter Jets, Needles and Topical Solutions. Annals of Biomedical Engineering 1-12 (2019)

·       Quetzeri Santiago, Impact of a microfluidic jet onto a pendant droplet, Soft Matter, 17, 7466 – 7475 (2021)

van der Ven, Microfluidic jet impact: spreading, splashing, soft substrate deformation and injection. Journal of Colloid and Interface Science, (636) 549-558 (2023).


  • You have experience (e.g., hold a PhD degree) in any of the following fields: bioengineering, physics, computational models, and have experience in research, which is apparent from publications in reputable academic journals, presentations in international scientific conferences, and other academic activities. We could discuss potential reorientation.
  • You have a creative mindset, excellent analytical and communication skills with a good team spirit for interdisciplinary and internationally oriented environment.
  • You conduct (fundamental and applied) research within a multidisciplinary environment;
  • You are active in networks for acquiring research funding, and have ambition and experience in working closely with companies and government agencies;
  • You have teaching experience (both lecturing and tutoring) at an internationally accredited university;
  • You have good communication skills and an excellent command of English;


  • A full-time position for 1.5 years, and the flexibility to work (partially) from home.
  • Your salary and associated conditions are in accordance with the collective labour agreement for Dutch universities (CAO-NU).
  • You will receive a gross monthly salary ranging from € 3.877,-  to € 5.090,-
  • There are excellent benefits including a holiday allowance of 8% of the gross annual salary, an end-of-year bonus of 8.3%, and a solid pension scheme.
  • A minimum of 232 leave hours in case of full-time employment based on a formal workweek of 38 hours. A full-time employment in practice means 40 hours a week, therefore resulting in 96 extra leave hours on an annual basis.
  • Free access to sports facilities on campus.
  • A family-friendly institution that offers parental leave (both paid and unpaid).
  • Excellent career support and courses for your professional and personal development.


The aim is for this postdoc position is to work together with two PhD students, balancing experimental and computational/simulation activities.

The objective is to investigate the fluid-structure interactions of liquid micro-jets impacting the skin. Depending on the applicants’ experience this team composition can be adjusted.

  • Experimental plan: To develop reliable methods to study skin dynamic properties. Here the team will ensure reproducible conditions to obtain parameters of skin at spatiotemporal scales not achieved before, by recording the impact of jets against skin with complimentary techniques.
  • – We foresee using: Atomic Force Microscopy (AFM) on ex vivo skin and conformal modulus sensor (CMS) indentation methods related to material properties. High-resolution imaging techniques (with dyes, particles, etc.) to study failure properties dependent on strain rates and loading directions. Injected samples will be analyzed with histological processing, confocal microscopy, optical coherence tomography (OCT), photoacoustic imaging, and fast X-ray imaging.
  • Modelling plan: The experimental results will help to untangle the inertia-driven dynamic loading provided by the jets from the observed elastic and dissipative response, i.e., deformation of soft substrates. We will adapt skin models (soft substrates) to our spatiotemporal conditions, and employ numerical simulation techniques to solve the inverse problem, i.e., identifying the dominant skin properties and predicting the jet velocity needed to puncture the skin.

We envisage using linear and bi-linear skin constitutive models considering multilayered skin. We will review and use those continuum methods (CM) that can describe nonlinearity, (poro)viscoelasticity, and load history. Properties like the Young’s modulus of the skin, and strain energy density functions will be devised for our experimental conditions, We will explore Finite Element Methods and employ a combination of Newtonian fluid equations, non-Newtonian visco-elastic models, e.g., on the Basilisk platform. We aim to model the rupturing of skin elements, as well as the dynamic evolution of the liquid jet free surface and how it splits into multiple (fluid) elements. Particle methods (PM) will be used to simulate the dynamics of discrete cells; their separation during penetration, and self-healing, e.g., detailed methods like Episim and MercuryDPM. Are you interested in this position? 

If you are interested? Please send your application via the ‘Apply now’ button and include:

·       A cover letter (maximum 1 page A4), emphasizing your specific interest, qualifications, motivations to apply for this position.

·       Email addresses of at least two references who are willing to send a letter of recommendation on your behalf.

·       A Curriculum Vitae, including a list of all courses attended and grades obtained, and, if applicable, a list of publications and references.

·       An IELTS-test, Internet TOEFL test (TOEFL-iBT), or a Cambridge CAE-C (CPE). Applicants with a non-Dutch qualification and who have not had secondary and tertiary education in English can only be admitted with an IELTS-test showing a total band score of at least 6.5, internet. TOEFL test (TOEFL-iBT) showing a score of at least 90, or a Cambridge CAE-C (CPE).

An interview with a scientific presentation will be part of the interview process.

For more information regarding this position, you are welcome to contact (Prof. David Fernandez Rivas +


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