Open Organoid Interface is an affordable, open-source system for recording neural signals from brain organoids, the 3D stem cell-derived models used to study disorders such as Alzheimer’s. It features flexible electrode arrays, custom-designed wells, and a plug-and-play headstage compatible with standard amplifier chips. By enabling high-resolution monitoring of neuronal activity and network formation, it offers researchers a powerful tool for modelling disease progression, testing therapeutics, and accelerating discoveries, at up to 1,000 times lower cost than existing commercial systems