An implantable acoustofluidic chip for on-demand and programmable drug delivery

Clinical drug delivery requires precise control, yet conventional methods suffer from fluctuating concentrations and low bioavailability. While implantable devices are promising for long-term therapy, wireless dosage control remains challenging. We report an implantable acoustofluidic chip for on-demand drug delivery. Fabricated via soft lithography and two-photon polymerization, the device integrates a drug-loaded hydrogel and a sharp-edge microcantilever array within a polydimethylsiloxane microchannel. Wireless ultrasound actuation induces acoustic streaming via the microcantilever array, generating a net pumping flow to drive drug release. In addition, the device also enables liquid-phase medications to be controllably released when the drug-loaded hydrogel is replaced by a liquid-phase formulation. Biocompatibility evaluation over a 144 h cell co-culture period confirms negligible cytotoxicity of the acoustofluidic chip. This work demonstrates a promising strategy for wireless, programmable implantable drug delivery.