CORDIS - EU research results

Penetrating microjets in soft substrates: towards controlled needle-free injections

Project description

Better control over tiny, powerful jets of fluids will streamline needle-free injection

The development of enhanced needle-free methods to inject liquids into soft substrates could have a significant impact on fields ranging from additive manufacturing to drug delivery. These methods rely on injecting a microfluid jet under high pressure guided by the equivalent of a capillary tube with a very small diameter opening. While it seems simple enough in principle, in practice it has been challenging to achieve. The EU-funded BuBble Gun project plans to enable clean penetration to just the right depth without splash-back or dispersion, which can cause contamination and alter the dose unpredictably. Relying on a combination of experimental and numerical methods, the team is characterising the stages of the process to enhance control, reproducibility and widespread application.


The needle-free delivery of liquid jets into soft and heterogeneous substrates, e.g. human tissue, has been hindered by (1) the need to reach specific penetration depths with energy efficient means, (2) the break-up of jets that impedes control over the dose delivery, and (3) liquid splash-back after impacting the substrate that cause cross-contamination between injections. BuBble Gun is aimed at overcoming these challenges. My team and I have recently uncovered new operational regimes of cavitation with continuous-wave lasers. My next goal is to study the energy partition between the creation of bubbles, the formation of liquid jets, and the penetration of these jets into soft substrates. Fundamental insights on energy partitioning will then be applied to achieve major breakthroughs in jet injection, by (1) controlling cavitation within microfluidic confinement, (2) tuning the rheology of jets emerging from confined cavitation, and (3) deriving the relationships between fluid dynamics and material properties governing jet injection into soft substrates. I expect to advance the knowledge at the intersection of microfluidics, physics, and bioengineering, to enable unprecedented control over cavitation, jetting, and injection phenomena. We will develop a portable energy- efficient injection platform by using ultra-high-speed imaging, and quantifying injections with experimental resolutions below the microsecond and micrometer scales. The rheological properties of the jets will be tuned with biocompatible additives to ensure cohesion, before injecting them into in-vitro targets and ex-vivo skin. Numerical models will assist untangling the influence of microfluidic configuration and material properties on the injection outcomes. The ultimate result will be the predictable, reproducible, and efficient injection of liquids that will enable a wide-range of technologies, such as additive manufacturing, coating modifications, the delivery of drugs and vaccinations.

Host institution

Net EU contribution
€ 1 500 000,00
7522 NB Enschede

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Oost-Nederland Overijssel Twente
Activity type
Higher or Secondary Education Establishments
Total cost
€ 1 500 000,00

Beneficiaries (1)