Session: 13-08-01: Mechanics and Materials of Soft Electronics I

Paper Number: 173939

Soft Multimodal Optoelectronic Devices for Cardiac Interfacing 

Heart disease remains one of the most challenging conditions to diagnose and treat, and it is the leading cause of death worldwide. Its complex mechanisms have driven the development of advanced tools to study heart function during normal rhythm, disease, and therapy. Multiparametric investigation of cardiac physiology is crucial for the diagnosis and therapy of heart disease. However, no method exists to simultaneously map multiple parameters that govern cardiac (patho)physiology from beating hearts in vivo. Soft microelectrode arrays (MEAs) have revolutionized cardiac research by enabling the monitoring of physiological properties and abnormal states with a high temporal resolution from electrically and mechanically active cardiomyocytes. MEAs alone cannot capture crucial biophysical signals like calcium, a key messenger that links electrical excitation to muscle contraction. Abnormal calcium cycling underlies many cardiac disorders including arrhythmias and heart failure. During each heartbeat, membrane depolarization triggers calcium release inside cells, which then modulates local electrical activity through calcium-dependent ionic currents. These processes work together and must be studied simultaneously to fully understand heart function. Optical mapping complements MEA approaches and records these parameters using appropriate fluorescent reporters. However, in vivo cardiac optical mapping remains a grand challenge and lags behind current motionless organ systems due to problems associated with persistent motion artifacts from heartbeat. The toxicity of small molecule fluorescent dyes and the spectral overlap of existing genetically encoded voltage and calcium reporters further prevent in vivo multiparametric cardiac measurements using optical mapping alone. In addition, the temporal resolution of cardiac optical mapping is limited by the inherent kinetics of the fluorescent reporters. To overcome these hurdles, there is growing interest in integrating electrical and optical methods for simultaneous, multiparametric cardiac mapping in vivo. Such an approach can reveal new insights into arrhythmia mechanisms and support the development of targeted therapies. Here, we introduce a novel cardiac sensing platform that achieves this integration with a wireless interface. Using advanced fabrication, we combine transparent microelectrodes, micro-scale LEDs, photodiodes, and optical filters into a soft, multilayer array. The transparent microelectrodes provide excellent electrochemical performance and allow co-localized fluorescence measurement without interference. Our device is biocompatible and records calcium fluorescence with sensitivity comparable to conventional imaging cameras. We demonstrate in vivo multiparametric mapping of electrical signals, calcium dynamics, and their interplay during normal rhythm, arrhythmia, and therapeutic interventions. This technology offers potential widespread use in cardiac research to support scientific discoveries and advance clinical life-saving diagnostics and therapies.

Presenting Author: Luyao Lu George Washington University

Presenting Author Biography: Luyao Lu received his Ph.D. degree in 2015 from the University of Chicago. He was then a postdoctoral fellow at the University of Illinois Urbana-Champaign and Northwestern University from 2015 to 2018. He joined George Washington University in August 2018 where he is currently an Associate Professor in Biomedical Engineering. His research focuses on innovating bioelectronic technologies, including designing soft electric/semiconductor materials and devices and creating advanced classes of implantable, wearable, and lab-on-a-chip optoelectronic tools, for applications in basic physiology investigations, organs-on-chips, and personalized medicine. He is an author of >30 peer-reviewed publications (>8,000 cites). His research has been recognized by multiple awards, such as the NSF CAREER Award (2024).

Authors:

Luyao Lu George Washington University