Capacitive Proximity Communication With Distributed Alignment Sensing for Origami Biomedical Implants

Origami implant design is a 3D integration technique which addresses size and cost constraints in biomedical implants. This paper presents a capacitive proximity interconnect scheme that enables chip-to-chip communication across folds in the Origami implant, allowing increased flexibility of chip placement and orientation. The capacitive plate array senses link quality and chip-to-chip alignment, and adapts the data rate at each plate accordingly, shutting down poorly-coupled links to save power. Instead of using separate plate arrays for alignment sensing and communication, this interconnect embeds the alignment sensor and transceiver arrays within the same set of plates, so that link quality can be measured at the communications plates directly, thus simplifying their adaptation to alignment. In order to save power and area, the sensor circuitry is distributed across the array and shares functional blocks with the transceiver. Data rates from 10–60 Mbps are achieved over 4–12 µm of parylene-C, with efficiencies up to 0.180 pJ/bit.