On May 22, the research team led by Zang Jianfeng and Tang Hanchuan from the School of Integrated Circuits at Huazhong University of Science and Technology had their paper published in Science Advances. The paper, titled "Bandgap-enabled ultrasound tissue marking by a biodegradable metastructured hydrogel implant," introduces a fully hydrogel-based, biodegradable ultrasound tissue marker that can be injected using an 18G puncture needle. This marker comprises a hydrogel matrix with internally arranged air channels in a periodic pattern. Its compact size, combined with its acoustic bandgap properties, allows it to effectively reflect ultrasound waves. When tissue deformation occurs, the internal microstructure of the marker deforms as well, leading to a frequency shift in the reflected sound waves. This enables precise marking of tissue positions. Furthermore, the marker demonstrates excellent biocompatibility and can naturally degrade within the body, eliminating the need for a secondary surgical procedure for removal.