Flexible electronic/optoelectronic microsystems with scalable designs for chronic biointegration

Abstract

Flexible biocompatible electronic systems that leverage key materials and manufacturing techniques associated with the consumer electronics industry have potential for broad applications in biomedicine and biological research. This study reports scalable approaches to technologies of this type, where thin microscale device components integrate onto flexible polymer substrates in interconnected arrays to provide multimodal, high performance operational capabilities as intimately coupled biointerfaces. Specificially, the material options and engineering schemes summarized here serve as foundations for diverse, heterogeneously integrated systems. Scaled examples incorporate >32,000 silicon microdie and inorganic microscale light-emitting diodes derived from wafer sources distributed at variable pitch spacings and fill factors across large areas on polymer films, at full organ-scale dimensions such as human brain, over ∼150 cm2. In vitro studies and accelerated testing in simulated biofluids, together with theoretical simulations of underlying processes, yield quantitative insights into the key materials aspects. The results suggest an ability of these systems to operate in a biologically safe, stable fashion with projected lifetimes of several decades without leakage currents or reductions in performance. The versatility of these combined concepts suggests applicability to many classes of biointegrated semiconductor devices.

Multifunctional Flexible Biointerfaces for Simultaneous Colocalized Optophysiology and Electrophysiology

“…[ 9,60,61 ] In addition, this multifunctional platform could be easily translated to neuroscience applications, such as miniaturized implantable optoelectronic neural interfaces for bidirectional monitoring and modulating neural activity, [ 62,63 ] brain–machine interfaces, [ 64,65 ] closed‐loop therapeutic deep brain stimulation, [ 66,67 ] etc. Ongoing and future research will focus on developing scale‐up fabrication strategies, [ 68 ] high‐performance nanogrid electrodes with subcellular resolution to enable recordings from single cells, and large‐scale multisite implantable arrays for chronic in vivo cardiac, neural, and skeletal muscle optical interventions with electrophysiological recordings.…”

Surface‐Mediated Interconnections of Nanoparticles in Cellulosic Fibrous Materials toward 3D Sensors

“…However, making conductive traces or interconnects on or cross this type of materials is often difficult or too costly with the conventional methods largely due to high temperature sensitivity of the materials. [ 1–3 ] Printed electronics have demonstrated the viability for low‐cost manufacturing of ever‐smaller integrated electronic devices, especially using conductive nanomaterials. [ 4,5 ] On the large‐scale and high‐volume printing potential, such printed electronics are expected to enable wearable and portable devices, with a wide range of applications ranging from sensors, displays, solar cells, and other electronic circuits.…”

Bioinspired Prosthetic Interfaces

“…Further, Song et al designed large‐scale, flexible electronic microsystems with a transfer printing technique of electronic/optoelectronic microdies . An example of ≈32 000 microdie was printed onto a thin, flexible sheet of polyethylene terephthalate cut into the approximate outline shape of an adult brain model at actual size (≈150 cm 2 ) with different die concentrations for spatial resolution in the electrical mapping of different sensory functions.…”