Fungi and Oomycetes are microorganisms that can be pathogenic and grow invasively causing significant economic losses and diseases1. • These organisms grow by extending the cell at the tip. This involves turgor pressure, cell wall yielding and a dynamic cytoskeleton, giving rise to a protrusive force2,3. •A Lab-on-a-Chip platform, with integrated force sensor based on elastomeric micro-pillars, is allowing us to study the molecular mechanisms which enable the generation of protrusive force at the tip of invasively-growing hyphae. •A maximum force of 16 μN was measured for the oomycete Achlya bisexualis cultured on the chip.