Initial stages of laser-induced forward transfer using a release layer via hydrodynamic simulations

• Time-resolved shadowgraphy and hydrodynamic simulations are combined to study LIFT. • Aluminum flyers benchmark HELIOS simulations of laser-driven launch dynamics. • LIFT of polymers exhibits a narrow fluence window for intact pixel transfer. • Hydrodynamic modeling guides optimization of polymer LIFT process conditions. Laser-induced forward transfer (LIFT) is a versatile technique for controlled thin-film deposition, yet the early-time dynamics governing flyer launch, shock formation, and material integrity remain insufficiently understood, particularly for polymers. Here, we combine time-resolved side-view shadowgraphy with one-dimensional (1D) hydrodynamic simulations to investigate LIFT of aluminum (Al) and polyisobutylene (PIB) films assisted by triazene polymer (TP) sacrificial layers under nanosecond UV irradiation. Al flyers are first used as a benchmark system to validate the hydrodynamic model against established experimental data, enabling assessment of flyer position–time trajectories and shock-wave evolution in air and vacuum. Polymer LIFT is then examined using 150 nm TP/60 nm PIB donor stacks at laser fluences of 200, 350, and 600 mJ/cm 2 . Shadowgraphy reveals a transition from barely detectable launch at low fluence, to efficient and coherent flyer ejection at intermediate fluence. At high fluences an overdriven regime is reached, characterized by excessive heating and material consumption. The simulations reproduce key experimental features, including the coupled departure of TP and PIB from the donor and the fluence-dependent loss of flyer integrity. Comparison between metal and polymer systems highlights the role of sacrificial-layer thickness, material response, and shock–flyer interaction in determining transfer quality. Overall, this combined experimental–simulation approach clarifies the process window for intact polymer pixel transfer and shows that hydrodynamic modeling can provide a useful tool for interpreting time-resolved LIFT diagnostics, provided that the geometrical and material-response limitations of the modeling framework are taken into account.