A pumpless unidirectional perfusion system for Vessel-on-Chip models utilising Tesla Valves

This study presents a pumpless unidirectional perfusion system using Tesla Valves (TV’s) and a rocking platform to replicate physiological blood flow in a Vessel-on-Chip (VOC) model. Unlike traditional pump-based systems, this setup eliminates moving parts, enhancing simplicity, cost-efficiency, and miniaturization. Multiple TV designs were evaluated by measuring flow rates under specific pressure drops, with diodicity used to identify the most effective configuration. The optimal TV was integrated into a VOC system consisting of two reservoirs connected by a VOC and TV channel. A hydraulic-electrical analogy was used to model the system, estimating backflow and wall shear stress (WSS). The results showed the system could produce the necessary pressure and WSS for liver sinusoidal endothelial cell studies. However, significant backflow was calculated, preventing truly unidirectional flow. This limitation renders the system unsuitable for organ-on-chip (OOC) models requiring unidirectional perfusion. To address this, future work should aim to reduce backflow, potentially through enhanced valve geometry or incorporating multiple TV’s to the VOC channel. Despite its limitations, this research demonstrates the potential of Tesla Valve-based pumpless systems, offering advantages in simplicity and scalability, and laying groundwork for more efficient microfluidic perfusion systems in OOC applications.