“Safety Valve”: A Metal-Based, Self-Securing Switchable Microvalve for Medical Applications

Konferenz: MikroSystemTechnik Kongress 2021 - Kongress
08.11.2021 - 10.11.2021 in Stuttgart-Ludwigsburg, Deutschland

Tagungsband: MikroSystemTechnik Kongress 2021

Seiten: 4Sprache: EnglischTyp: PDF

Durasiewicz, Claudia Patricia (Fraunhofer EMFT Research Institution for Microsystems and Solid State Technologies, Munich, Germany)
Hoelzl, Wolfgang; Schrag, Gabriele (Chair for Physics of Electrotechnology, Technical University of Munich, Munich, Germany)

Drug dosing systems require fail-safety in order to prevent patients’ harm. We present a passive microvalve without external control or energy consumption designed to regulate the flow path of a microfluidic drug dosing system. The metal-based self-securing switchable microvalve for medical applications is experimentally characterized for water flow rates and fluidic resistance. Additionally, we characterize a microfluidic delivery system comprising a piezoelectric mi-cropump in combination with the microvalve for delivered water flow rate and find a maximum of (13.8 ± 0.7) ml/min, as well as fail-safe state leakage rates with an average of (31.8 ± 5) mul/min. Among the manufactured and tested mi-crovalves, several valves exhibit pressure-induced flow obstruction. Dedicated FEM simulations of the flow inside the microvalve show flow field-induced phenomena as reasons for this malfunctioning, which lays the basis for a deeper understanding of the functionality of the component.