Printed circuit boards (PCBs) are the hidden foundation of every modern device, yet their rigid, single-use design creates a global e-waste crisis. This talk explores how reimagining PCBs for circularity by making them reusable, reconfigurable, and dissolvable reshapes not just hardware but also human–computer interaction. I will present three systems: SolderlessPCB, which eliminates solder so chips can be removed and reused multiple times; PCBRenewal, which allows a single board to be reconfigured across applications, from a radio to a Game Boy; and DissolvPCB, the first fully dissolvable, 3D-printed PCB that recovers up to 98% of materials after use. Beyond their technical contributions, these systems demonstrate how sustainability is also an HCI challenge, enabling designers, educators, and everyday makers to assemble, repair, and repurpose electronics in new ways. By reframing circularity as an interactive design principle, this work shows how computing can align with human values of repair, adaptability, and sustainability.