Circulating tumor cells (CTC) are important clinical markers for liquid biopsy and can be used for early cancer diagnosis. But its quantity in the human body is very rare, accounting for only one billionth of the normal blood cell count. To find it, it's like looking for a needle in a haystack. In recent years, both Chinese and foreign scientists have been trying to accurately locate circulating tumor cells from the blood. Recently, a team led by Liu Lei, a researcher at the School of Materials Science and Engineering and the Institute of New Materials Research at Jiangsu University, has developed a multifunctional biomimetic flexible film. This type of membrane not only has a keen eye and a smart brain, which can accurately capture circulating tumor cells, but also has a biomimetic mechanism comparable to the human environment, which can bring circulating tumor cells back unscathed and release them in the laboratory for further detection. In the blood sample detection of breast cancer patients that has been carried out at present, the detection data of this membrane is highly consistent with the postoperative immunohistochemical staining results, and the accuracy rate is 100%. At the same time, it can classify, capture, and selectively separate circulating tumor cells, achieving molecular typing diagnosis of cancer. The relevant research results are published online in the international journal Advanced Materials. It is well known that cancer cells are mutated cells that are prone to metastasis and spread, and can be transferred to other parts of the body through the circulatory or lymphatic systems. During the metastasis process, circulating tumor cells will detach from the tumor tissue and enter the bloodstream. If circulating tumor cells can be accurately captured, warning signals can be obtained earlier than conventional tumor marker detection in physical examinations, indicating the potential risk of cancer in human tissues. "But circulating tumor cells are not only limited in number, but also very 'cunning'. They have different surface markers and can 'cross dress', sometimes wearing a' vest 'and sometimes putting on a' coat ', making it difficult to identify." Liu Lei introduced that due to the rarity and surface heterogeneity of circulating tumor cells, the detection of circulating tumor cells faces great challenges. Capturing the cunning circulating tumor cells is the first step in detecting and distinguishing tumors. At present, there is already nano magnetic bead technology internationally, which uses magnetic field recovery to capture circulating tumor cells. But this technology has a serious flaw: after capturing circulating tumor cells through a "network" of countless magnetic beads, the cells will "ingest" magnetic beads with a diameter of only a hundred nanometers, leading to the death of circulating tumor cells. In this way, doctors are unable to further analyze the valuable biological information carried by cells. In 2018, Liu Lei focused his research on the capture of circulating tumor cells. He plans to design an intelligent biomaterial interface that integrates targeted recognition function. "The interface of this material is like a clever detective, able to accurately identify circulating tumor cells, extend a 'big hand' to tightly grasp them. At the same time, it can be released as needed, causing circulating tumor cells to detach from the interface, providing a basis for downstream analysis." Liu Lei said. In order to achieve the capture and separation of circulating tumor cells, Liu Lei's team has created an intelligent biological interface material system with dynamic biological activity by creating a strong and soft biomimetic membrane. At first, we tried a quartz interface similar to a glass sheet. However, the quartz sheet was large and brittle, making it impossible to cut