The microfluidic acoustoinjection device is designed with computer-aided design (CAD) software, QCAD-pro (Ribbonsoft, Switzerland) and transferred onto a photoresist-layered silicon wafer (master wafer) with a micro Pattern Generator µPG 101 (Heidelberg Instruments, Germany). Fig. and S1 show a precise sketch of our designs and explain the constructions. As previously described , for the production of the master wafer, negative photoresist (SU8-3025, MicroChem, USA) is spin-coated (Laurell Technologies Corp., USA) onto a silicon wafer at 2650 rpm to achieve a uniform coating of 30 µm thickness. The wafer is then placed on a hot plate for a 5 min soft bake at 65 °C, then ramped slowly to 95 °C and held for 15 mins. The CAD design is exposed onto the photoresist with the writing mode II setting of the micro Pattern Generator. The output power of the laser is set to 50 mW with a pixel pulse duration of 20 %. For the post exposure bake, the wafer is placed on a hot plate for 1 min at 65 °C and then ramped and held at 95 °C for 5 min. The unexposed parts of the resist are removed with mr-DEV 600 (MicroChemicals, Germany). The following hard bake is carried out in an oven at 150 °C for 15 min. To fabricate the microfluidic device, Polydimethylsiloxane (PDMS) (Sylgard 184, Dow Corning, USA) is mixed at a 9:1 (w/w) ratio and poured over the master wafer, degassed for several minutes in a desiccator, and cross-linked for 2 h at 65 °C in an oven. After hardening, the PDMS slab is peeled off of the wafer and a biopsy punch is used (World Precision Instruments, USA) to punch holes for the fluid inlets/outlets (0.5 mm) and electrodes (1.0 mm). Prior to the attachment of the PDMS to a 2 inch, double-side polished, lithium niobate (LiNbO3) piezoelectric crystal (128° Y-cut, 0.25 mm, Precision Micro-Optics, USA), both materials are activated using an oxygen plasma (PVA TePla 100, PVA TePla, Germany; 0.45 mbar, 200 W, 20 sec). After activation, the PDMS slab is pressed on the lithium niobate substrate and heated for at least 1 h at 65 °C. The IDT channels are directly integrated into the microfluidic design and subsequently filled with liquid metal. For this, the microfluidic device is heated to 80 °C on a hot plate and a low melting-point alloy (In0.51Bi0.325Sn0.165, Indium Corporation of America, USA) is molten injected into the IDT channels. Electric wires are connected to the melted solder and fixed with UV hardening glue (Loctite 352, Henkel, Germany) after allowing the molten solder to cool down and harden.