Microscopic sensors using optical wireless integrated circuits

Abstract

We present a platform for parallel production of standalone, untethered electronic sensors that are truly microscopic, i.e., smaller than the resolution of the naked eye. This platform heterogeneously integrates silicon electronics and inorganic microlight emitting diodes (LEDs) into a 100-μm-scale package that is powered by and communicates with light. The devices are fabricated, packaged, and released in parallel using photolithographic techniques, resulting in ∼10,000 individual sensors per square inch. To illustrate their use, we show proof-of-concept measurements recording voltage, temperature, pressure, and conductivity in a variety of environments.

Energy Harvesting in Nanosystems: Powering the Next Generation of the Internet of Things

“…Scaling down device dimensions below 1 mm can reduce conversion efficiency due to perimeter non-radiative recombination effects in semiconductors (Moon et al, 2017), where passivation of semiconductor surfaces remains a key to achieving high energy conversion efficiency. At higher power density, untethered self-powered sensors have been demonstrated at dimensions of 100 µm (Cortese et al, 2020).…”

Fabrication of Injectable Micro-Scale Opto- Electronically Transduced Electrodes (MOTEs) for Physiological Monitoring

“…While the MOTE's two main pillars, PVLED and the CMOS have individually been studied in detail [12], [14], [18], discussion of the associated integration challenges has been lacking. Given the MOTE's size scale, wire-bonding is out of the question for interconnecting PVLED and MOS: a single wirebond-pad footprint is larger than the MOTE.…”

“…We have instead photolithographically integrated the PVLED and the CMOS to result in a scalable and robust system. We have optimized the polymer-based transfer method [18], [19] and dielectric cladding to allow MOTEs to survive in a mouse brain for two months (and counting). We also discuss a practical insertion method that has been lacking -a μ-pipette approach to allow users to manipulate and insert the MOTEs with a minimal learning curve.…”

“…Following the dielectric removal, we transfer an AlGaAs μLEDs array that have been tailored to match the CMOS layout, using poly (methyl methacrylate) (PMMA) transfer techniques often used in 2D materials transfers [18], [19]. while both the V DD and the V SS aluminum pads are directly below the cathodic layer of the PVLED, they do not form ohmic contacts alleviating leakage concerns.…”

Autoperforation of two-dimensional materials to generate colloidal state machines capable of locomotion

“…It is encouraging to note how the nascent eld of CSMs has been steadily expanding. [24][25][26] Despite this, several technological challenges persist. One challenge specically addressed in this work is locomotion.…”