Chronic kidney disease is a worldwide and ever-growing health crisis in which end-stage patients largely depend on intramural dialysis, placing a heavy burden on their life and on European health care systems. KIDNEW develops groundbreaking and modular technology to enable an implantable artificial kidney with better functional kidney replacement therapy (KRT) than currently available, without need for immunosuppressive drugs and at reduced costs. It provides proof of concept on three breakthrough technologies: 1. Solid-state miniature ultra-high flux silicon (Si)-based filter with a high-density of uniform nanopores through novel block copolymer self-assembly, and with novel hemocompatible biomimetic polymer polymer brush coating connected to a photonic clotting monitoring sensor and (thrombolytic) cleansing tool; 2. Solid-state bioreactor-grown kidney tubule cell monolayers on novel biomimetic Si-wafer based membrane with bioimpedance-based monolayer integrity monitoring and monolayer repair functionality using growth-factors; 3. Solid-state integrated functional biohybrid filter and tubule exchange units stacked in parallel in a multichip to demonstrate functional implantable KRT in goats. An implantable bioartificial kidney will provide more effective, more physiological, and economical sustainable KRT than dialysis. Eco-friendliness of proposed technologies, in line with the EU Green Deal, has recently been highlighted by the European Kidney Health Alliance. On the short to mid-term, the filter and/or tubule unit may enter niche-markets for extracorporeal use, in complementing rather than replacing current dialysis solutions. KIDNEW brings together scientists from the fields of clinical and regenerative nephrology (UMC Utrecht, NL), regenerative pharmacology (University Utrecht, NL), chip technology (Imec NL and Imec BE), optical sensing (Optofluid Technologies OÜ, EE), blood compatible coatings (CNRS, FR), and membrane technology (Me-Sep, PL).