Electronic devices represent one of the most sophisticated human-made tools due to their powerful capabilities in data acquisition and processing, but their 2D configurations are insufficient to interact and communicate with 3D biological tissues. Current approaches to mitigate this 2D-3D-mismatch mainly involve flexible electronics and 3D printing. However, flexible electronics can only interact with biology through limited 2D surfaces, and 3D printing fails to utilize most of the high-performance materials and devices developed in the electronics industry.
Mengdi Han, an Assistant Professor of Biomedical Engineering at Peking University, developed a series of multiscale 3D bioelectronic devices to address some fundamental limitations in interfaces. He built 3D bioelectronic systems both in large-scale and small-scale, through a set of advanced manufacturing schemes that are compatible with the microelectronic process and can work in a parallel fashion.
The bioelectronic systems can possess 3D geometries at a small scale to serve as desired interfaces for cells, tissues, or organoids. A specific example is the open-network electronic scaffolds designed for 3D interaction with dorsal root ganglion neural networks. Such 3D electronic scaffolds not only provide structural support to guide the cell growth and migration but also have capabilities in recording electrophysiological signals and inducing electrical stimulations in 3D space. Future opportunities for this type of 3D electronic scaffold include continuous assessment of cell behaviors, multimodal neuromodulation, and many others.
Mengdi Han's work leverages the most advanced electronic devices and materials in state-of-the-art semiconductor industries and allows bioelectronics to interact with biology across the 3D surfaces or through the volumes. The multiscale 3D bioelectronics can serve as desired interfaces for cells, tissues, and organs, targeting and probing rich biological information in 3D spaces and providing multimodal, programmable modulations. An example is the ‘instrumented’ surgical tool with multiplexed, multimodal sensors integrated on a soft balloon that can deflate and inflate into various 3D geometries.
Studies on Langendorff-perfused animal and human heart models demonstrate the capabilities in the high-density spatiotemporal mapping of electrophysiological signal, temperature, and pressure, as well as programmable stimulation. The highly customizable 3D geometries of the bioelectronics enable conformal contacts to curved cardiac tissues as well as other organs, thereby providing high-fidelity diagnosis and efficient therapy in many interactions with the human body.
The innovation also has broad potentials in other areas, including but not limited to mechanical/optical metamaterials, microrobotics, micro/nano hierarchical structures, and energy devices.