Ah-Hyoung Lee 1, Jihun Lee 1, Vincent Leung 2, Arto Nurmikko 1,3
1School of Engineering, Brown University, Providence, RI, 02912, USA.
2Electrical and Computer Engineering, Baylor University, Waco, TX, 76798, USA.
3Carney Institute for Brain Science, Brown University, Providence, RI, 02912, USA.
A.-H.L. and J.L. contributed equally to this work.
CORRESPONDING AUTHOR : Arto Nurmikko
Wearable and implantable microscale electronic sensors have been developed for a range of biomedical applications. The sensors, typically millimeter size silicon microchips, are sought for multiple sensing functions but are severely constrained by size and power. To address these challenges, a hardware programmable application-specific integrated circuit design is proposed and post-process methodology is exemplified by the design of battery-less wireless microchips. Specifically, both mixed-signal and radio frequency circuits are designed by incorporating metal fuses and anti-fuses on the top metal layer to enable programmability of any number of features in hardware of the system-on-chip (SoC) designs. This is accomplished in post-foundry editing by combining laser ablation and focused ion beam processing. The programmability provided by the technique can significantly accelerate the SoC chip development process by enabling the exploration of multiple internal circuit parameters without the requirement of additional programming pads or extra power consumption. As examples, experimental results are described for sub-millimeter size complementary metal-oxide-semiconductor microchips being developed for wireless electroencephalogram sensors and as implantable microstimulators for neural interfaces. The editing technique can be broadly applicable for miniaturized biomedical wearables and implants, opening up new possibilities for their expedited development and adoption in the field of smart healthcare.