UC Irvine researchers engineer a light-powered biohybrid cardiac interface

• UC Irvine researchers have designed a device that makes heart tissue respond to pulses of light.
• Combining polymer layers with heart cells, the invention can be used in the future to test cardiac therapeutics safely and effectively.
• Other possible applications include soft, biocompatible heart patch implants controlled by light.
• Funding was provided by the National Heart, Lung and Blood Institute of the National Institutes of Health.

Irvine, Calif., March 24, 2026 - Researchers at the University of California, Irvine have developed a polymeric biohybrid cardiac device that harnesses the power of light to electrically and mechanically control living heart tissue without the use of metal electrodes.

The innovation represents a leap forward in how scientists study heart disease, test cardiac drugs and potentially treat life-threatening arrhythmias. The project is outlined in a paper published today in the journal Cell Biomaterials.

The invention works by coupling engineered layers of optoelectronic polymer film, which can convert light into an electrical current, directly with living cardiac cells. When pulsed with gentle, visible green light, the material generates photocurrents that stimulate the heart cells to contract in synchrony, mimicking a healthy human heartbeat. The result is a soft, flexible, light-driven biohybrid device that overcomes longstanding limitations of traditional, metal electrode-based cardiac stimulation.

"What we've built is essentially a light-powered interface that speaks in electrical and mechanical pulses, the same language as the heart, without any of the drawbacks of rigid electrodes, such as tissue damage or contamination risk over long-term use," said co-author Herdeline "Digs" Ardoña, UC Irvine assistant professor of chemical and biomolecular engineering.

The device is produced by blending and layering conjugated polymers on an elastomeric polymer base, whereby the topmost layer has donor-acceptor junctions capable of generating photocurrents at the surface when illuminated. Another composite material layer serves as an interface between this active layer and the biological environment, improving charge transport, stability in aqueous cell culture conditions and compatibility with living cells.

"When submerged in cell culture medium and illuminated, the polymeric blend generates a charge-transfer state that drives ionic redistribution at the polymer-electrolyte interface - effectively creating a gentle, localized electrical stimulus for heart cells growing on the surface," said lead author Yuyao Kuang, who recently completed a Ph.D. in chemical and biomolecular engineering at UC Irvine. "This photocurrent generation mechanism is distinct from optogenetics, which requires genetic modification of cells to introduce light-sensitive proteins, making our approach applicable to native, unmodified cardiac tissue."

Neonatal rat ventricular myocytes, a standard research model for human cardiac cells, were cultured on the optoelectronic substrate in an anisotropic, micropatterned arrangement that closely mimics the organized fiber architecture of the native heart muscle. The team then fashioned this layered construct into a muscular thin film with a cantilever geometry, allowing the researchers to directly observe and quantify the bending motions produced by cardiac contractions in response to light pulses, a measurement of both electrical pacing and mechanical function.

Ardoña said that two of the innovation's most immediately impactful applications are in pharmaceutical drug screening and cardiac disease research. Currently, non-animal-based testing of how a new drug affects heart tissue in the laboratory relies on systems that use either rigid electrodes to pace cardiac contractions, which can introduce artifacts and contamination, or simplified models that don't replicate the complex electromechanical environment of the beating heart.

"What we've built is essentially a light-powered interface that speaks in electrical and mechanical pulses, the same language as the heart, without any of the drawbacks of rigid electrodes, such as tissue damage or contamination risk over long-term use," says study co-author Herdeline "Digs" Ardoña, UC Irvine assistant professor of chemical and biomolecular engineering. Steve Zylius / UC Irvine

With the UC Irvine biohybrid platform, researchers can apply a candidate drug directly to the living, light-paced cardiac tissue and observe in real time how the medication affects the heart's response to external electrical pacing and mechanical strain, tissue contractile strength, and even long-term structural remodeling of protein networks inside cells, all in a single, integrated experiment. This creates a far more realistic picture of a drug's true effect on cardiac function than other existing in vitro tools can provide, according to Ardoña.

Beyond the laboratory, the team envisions future iterations of this technology serving as implantable cardiac patches, conformable devices that wrap around diseased or damaged heart muscle and deliver precise, light-driven pacing therapy. Because the platform is mechanically compliant and avoids rigid metal components, it's inherently better suited to the soft, constantly moving environment of the heart than conventional pacemaker electrode technologies. The team is working toward versions of this platform that are responsive to longer wavelengths of light, such as near-infrared, which can pass through tissue layers.

Joining Ardoña, Kuang and other UC Irvine affiliates for this project were researchers from UC Santa Barbara and Virginia Tech. Funding was provided by the National Heart, Lung and Blood Institute of the National Institutes of Health.

About the University of California, Irvine: Founded in 1965, UC Irvine is a member of the prestigious Association of American Universities and is ranked among the nation's top 10 public universities by U.S. News & World Report. The campus has produced five Nobel laureates and is known for its academic achievement, premier research, innovation and anteater mascot. Led by Chancellor Howard Gillman, UC Irvine has more than 36,000 students and offers 224 degree programs. It's located in one of the world's safest and most economically vibrant communities and is Orange County's second-largest employer, contributing $7 billion annually to the local economy and $8 billion statewide. For more on UC Irvine, visit www.uci.edu.

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