UC Irvine

The rapid growth of wearable electronics has generated an influx of research in developing highly flexible, stretchable materials and sensors that can conform to the human body. Developing flexible soft sensors that are capable of withstanding large amounts of mechanical stress can enable novel continuous health monitoring devices. However, existing functional materials are rigid and brittle which are not able to flex and stretch with the human body. Therefore, there is a need to engineer materials that are capable of withstanding mechanical stress to develop conformable wearable electronics for continuous health monitoring applications.

The work presented here introduces a thermally induced shrinking fabrication platform using pre-stressed thermoplastics to create highly wrinkled structured thin films for stretchable electronic sensing applications. Specifically, mechanically flexible and stretchable wrinkled gold (Au) and carbon nanotube (CNT) thin films were fabricated for stretchable conductive wire, strain, and pressure applications. Electrical-mechanical characterization studies have shown that these wrinkled functional thin film materials, in comparison to its flat counterpart, were able to withstand large amounts of tensile stress and mechanical pressure before electrical failure. When supported by elastomeric substrates, these wrinkled thin film materials may be used as stretchable wires and sensors for wearable applications on the human body. Finally, I will report on potential wearable applications demonstrating continuous health monitoring applications including human motion detection and blood pressure estimation.