When Butterfly Meets Photoacoustic Effect

Abstract

The photoacoustic effect converts light into sound, bridging optical excitation and acoustic generation. However, existing photoacoustic systems remain largely confined to specialized applications because the generated signals are weak and typically require expensive lasers and delicate materials. In this paper, we demonstrate for the first time that natural butterfly wings can function as highly effective photoacoustic materials, enabling strong and practical photoacoustic generation using an ordinary LED. The key principle is that butterfly wings are not only excellent light absorbers but also support efficient light-heat-acoustic conversion, owing to their unique ultra-thin and lightweight membrane structures. In this work, we establish a model of the butterfly photoacoustic effect, providing a theoretical foundation for future research. We address critical technical challenges, including weak signal, as well as practical challenges such as environmental interference, realizing the first end-to-end butterfly photoacoustic system. Results show that our system achieves strong photoacoustic outputs exceeding 70 dB—comparable to a speaking voice—using off-the-shelf LEDs and naturally deceased butterfly specimens. We demonstrate the application potential of the proposed butterfly photoacoustic effect by using the butterfly as a bio-speaker for audible information delivery and for fine-grained ultrasound sensing. Our system harnesses this intriguing cross-energy phenomenon for practical applications and opens new opportunities for bio-inspired designs.