Abstract
Conventional needle injections and mechanical drilling often cause patient discomfort, contamination risk, and thermal tissue damage. Electromagnetic actuator-driven jet injection (EM-JI) presents a promising alternative; however, existing studies rarely integrate actuator design, numerical modeling, and experimental validation into a unified framework. This study develops and validates an experimental–computational framework for EM-JI aimed at biomedical delivery and micromachining. A compact electromagnetic actuator, powered by a 5400 μF/600 V capacitor bank and a 1600-turn coil, generated pulsed liquid jets through interchangeable nozzles. Jet dynamics were characterized using high-speed imaging, polyvinylidene fluoride (PVDF) sensors, and computed tomography/optical coherence tomography (CT/OCT) imaging, while transient computational fluid dynamics (CFD) simulations employing the Volume of Fluid (VOF) method with SST turbulence modeling captured jet evolution. Numerical and experimental results showed strong agreement, with deviations within 10%. The system achieved jet velocities up to 140 m/s and impact pressures above 20 MPa, surpassing thresholds for needle-free injection. In soft-tissue analogs, penetration depths reached 41 mm with 30 mm dispersion width, closely matching CFD predictions. Bone drilling tests produced 4.52 mm depth at 80 pulses, yielding a 0.113 mm/mL efficiency—over twice that of conventional waterjet drilling.