Session: Research Posters

Paper Number: 173178

Rubbery Optoelectronics and Optoelectronic Biohybrid Ink for Cardiac Stimulation and Tissue Engineering 

Introduction: Cardiovascular diseases remain a leading cause of mortality, and there is an urgent need for technologies that can seamlessly interface with the heart for both therapeutic and research purposes. Traditional electronic implants are often rigid, bulky, and incapable of conforming to the dynamic nature of cardiac tissues, leading to limitations in performance and potential tissue damage. To overcome these challenges, our research introduces two complementary approaches: (1) an ultrathin, rubbery bio-optoelectronic stimulator (RBOES) capable of delivering light-induced electrical stimulation, and (2) a bioprinted optoelectronically active cardiac tissue that integrates light-responsiveness with three-dimensional tissue constructs. Together, these works aim to revolutionize soft cardiac bioelectronics for future clinical and biomedical applications.

 

Contribution: This research contributes to both materials science and bioengineering by demonstrating two strategies for seamless cardiac integration: a stretchable, untethered optoelectronic device for direct cardiac stimulation, and a bioprinted tissue construct incorporating optoelectronic components. These platforms enable nongenetic, wireless cardiac modulation, opening new avenues in regenerative medicine, personalized therapy, and organ-on-chip systems. They provide foundational insight into coupling soft optoelectronics with dynamic, excitable tissues.

 

Methodology: The RBOES is constructed as a bilayer of a stretchable gold nanomesh conductor and a rubbery semiconducting nanofilm composed of a polymer blend. This nanofilm is produced via an air-water interfacial self-assembly method and laminated onto the conductor, resulting in a <500 nm-thick device with excellent softness, conformability, and photovoltage generation under pulsed light. Its performance is validated through ex vivo rat heart stimulation and in vitro studies on human iPSC-derived cardiomyocytes. Separately, the biohybrid cardiac tissue is fabricated via 3D bioprinting of cell-laden hydrogels integrated with microfabricated silicon-based micro-sized solar cells. These embedded micro-sized solar cells enable localized electrical stimulation upon light exposure, with spatiotemporal control across the tissue. Experimental validation includes electrophysiological response analysis and gene expression studies.

 

Results and Conclusions: The RBOES demonstrates robust mechanical stretchability (up to 20%) while maintaining consistent photovoltage output and strong, adhesive contact with dynamic cardiac tissue, owing to its ultrathin and intrinsically stretchable design. The device maintained optical-to-electrical conversion stability under cyclic strain and wet biological conditions, supporting its suitability for chronic applications. In vitro, human induced pluripotent stem cell–derived cardiomyocytes cultured on the RBOES exhibited enhanced beating rate, improved synchronicity, and long-term viability. Ex vivo experiments on Langendorff-perfused rat hearts showed that pulsed light stimulation using the RBOES could modulate cardiac rhythms in a spatially confined manner, without the need for direct wiring or genetic modification.

 

In addition, the bioprinted cardiac tissue construct integrates microfabricated silicon micro-sized solar cells directly into 3D cellular hydrogels using multi-material 3D bioprinting. These optoelectronic modules enable spatially addressable and temporally controlled electrical stimulation in response to light input. Under pulsed illumination, the tissue constructs exhibit synchronized contraction, indicating functional electrical excitation. Furthermore, gene expression analysis revealed the upregulation of cardiac maturation markers in stimulated tissues, suggesting the potential of these platforms for both therapeutic stimulation and in vitro cardiac development studies. The biohybrid constructs maintain structural integrity and viability over extended culture periods, supporting their relevance for long-term organ-on-chip applications.

Together, these results mark a significant step forward in the development of soft, bio-optoelectronic platforms that merge the mechanical compliance of biological tissues with functional electronic capabilities. These two complementary approaches - device-level stimulation and tissue-level integration - demonstrate that light-responsive platforms can achieve precise, wireless, and noninvasive control of cardiac electrophysiology. This opens promising pathways toward the design of next-generation implantable cardiac therapies, optogenetic-free modulation platforms, and responsive biohybrid systems for translational research.

Presenting Author: Zhoulyu Rao University of Illinois Urbana-Champaign

Presenting Author Biography: I am now a postdoctoral researcher at the University of Illinois Urbana-Champaign (UIUC). He received his Ph.D. in Materials Science and Engineering from the University of Houston in 2021, an M.S. in Chemistry from the University of Science and Technology of China in 2015, and a B.S. in Applied Chemistry from Xidian University in 2012. My research interest focuses on pioneering new electronic materials and devices to bridge the gap between engineering devices and biological systems, to overcome some great challenges in or related to imaging, healthcare, medicine, robotics, etc. To achieve this goal, my research spans from the creation of electronic materials/devices with high area coverage, ultrathin thickness, or softness/stretchability-outperforming counterparts achieved by traditional technologies, to validating the devices in small animal models.

Authors:

Zhoulyu Rao University of Illinois Urbana-Champaign
C. Yu University of Illinois, Urbana-Champaign