Covered with silk quilt, but have you used a silk hard drive

The world's first silk hard disk comes out, with the function of ordinary optical discs and can record life information

　　The rapid development of communication technologies such as 5G has brought about high-reliability and low-latency network connections. We will soon enter the era of "Internet of Everything". The surge of devices connected to the network will bring about a surge in data storage. How to break through the limitations of existing storage devices and achieve more efficient and larger capacity storage is the focus of current technical research.

　　In people's impression, the main purpose of silk is as a textile material, and the development of science and technology is constantly breaking through people's imagination. When silk meets modern civilization, it turns into a high-tech innovative material, which can not only store information, but also be implanted in the human body.

　　Recently, Tao Hu's research group from the Shanghai Institute of Microsystems, Chinese Academy of Sciences, and related research groups from the State University of New York, Stony Brook and the University of Texas at Austin, developed the world's first hard disk storage based on natural biological proteins—silk hard disk. Related achievements It was recently published in the internationally renowned journal "Nature Nanotechnology".

Large storage capacity and high stability are expected to be used in extreme environments such as outer space

　　Scientists have always been committed to the integration of life science technology and semiconductor technology. One of the important achievements of this type of research is to bring new ideas to information storage, such as high-capacity DNA storage technology, oligopeptide storage technology, etc. A storage technology based on biological media is constantly being developed.

　　Recently, scientists have developed high-capacity silk protein storage technology using silk fibroin as a storage medium. Based on the selective absorption of infrared light by silk fibroin, near-field infrared nanolithography is used to process high-density lattices on silk fibroin membranes. It realizes the writing of digital information and the reading of information for dot matrix imaging, thus realizing the storage function of silk protein.

　　According to scientific researchers, because silk protein can absorb infrared light, it is possible to use near-field infrared nanolithography technology to use silk protein as an optical disc to write and read digital information on it. The process of making a silk hard disk is a bit like a "pancake". Using near-infrared nanolithography to write information into a silk hard disk is like sprinkling sesame seeds on a pancake. After the whole process is completed, the surface of the "cake" is uneven. The trace is similar to the digital signal of "0" and "1", and the stored information can be obtained by decoding.

　　So far, the team has used this technology to realize the principle verification of the accurate recording, storage and "reading" of image and audio files such as "Bombyx worm eating leaves" and "empty valley bird song", and related technologies have applied for patents.

　　It is understood that this kind of memory developed with silk protein as the storage medium has many unique advantages: large storage capacity, 64GB of data per square inch; in-situ repeated erasing and writing; simultaneous storage of binary digital information and Biological information directly related to life activities; it can be implanted into organisms for long-term preservation, or it can be degraded in a controlled manner within a preset time.

　　It is worth mentioning that silk protein has good performance in mechanical strength, biocompatibility, biodegradability, easy functionalization and adjustable water solubility. These characteristics give the silk hard disk extremely high stability, enabling it to work stably for a long time in harsh environments such as high humidity, high magnetic field or strong radiation. The silk hard disk is placed in a relative humidity of 90% or a 7 Tesla magnetic field or 25 thousand. In the strong radiation environment of Gray, the stored information will not be lost. Therefore, the silk protein storage technology is expected to be applied to extreme environments such as outer space.

Adding biomarkers can coexist biological information and digital information

　　In 1978, the U.S. Voyager 1 probe carried a record "Voices of the Earth" into space for the first time. At that time, in order to withstand extreme environments, this record was made of gold-plated copper plates. Not only was it expensive, but it could only store a single record. Digital information.

　　If it is a silk hard disk that is brought into space, then the human life code is expected to be preserved and further studied in outer space. Because the silk hard disk can store not only digital information, but also biological information.

　　"Silk protein memory can not only store digitally coded information such as images, audio, text, etc., like ordinary semiconductor hard disks, but also provide a huge platform for the storage of active biological information, which can be used to collect and store biological information and can store biological DNA. And blood samples.” Tao Hu, the initiator and main inventor of the technology and director of the 2020 Frontier Laboratory of Shanghai Institute of Microsystems, said that by regulating the degradation rate of proteins, this memory can also be destroyed in a controlled manner according to a preset time sequence. So as to keep information confidential.

　　So, why can the silk hard disk store active biological molecules?

　　According to scientific researchers, the formation process of silk protein memory is a process of turning silk into a silk protein solution and then spinning it into a thin film. If you want to store active biomolecules, after turning the silk into a silk fibroin solution, you can incorporate markers with hemoglobin, albumin, glucose and other vital features into it, which completes the entire process of vital information storage If high-density dot matrix processing is performed on the silk fibroin membrane by means of laser and other means, and binary digital coding is used, digital information and life information can be stored on the silk hard disk at the same time.

　　According to reports, silk protein is a water-repellent material. It will form a waterproof and gas-proof compact structure at a certain nanometer scale, and protect the easily damaged organic molecules such as protein, glucose, DNA and so on. .

　　In addition, the silk hard disk can be implanted into a living body after surgery, and because of the good biocompatibility of silk protein, there is basically no rejection reaction after being implanted in the body.

Technology maturity needs to be verified, and there is still a long way to go before large-scale commercialization

　　The reporter of Science and Technology Daily learned that the memory can store 64GB of data on an area of ​​one square inch (about 6.45 square centimeters). If converted into traditional semiconductor memory, the capacity of a 3.5-inch silk protein memory exceeds 0.5TB (512GB). .

　　“A 3.5-inch (silk protein) silk protein storage uses less than 0.1 gram of silk. According to this calculation, a single cocoon can produce a storage space of 1-3TB, while a natural silk weighing about 1.5 kg The silkworm cocoons needed can be made into tens of thousands of natural silk storages of this scale." Tao Hu said. This means that if the silk protein memory can be mass-produced, the production cost of the memory will be greatly reduced.

　　So, will the quality of the silk hard drive be affected by the different origin of silkworm cocoons? How to preserve silk protein? Can silk hard drives be mass-produced in the future? To these questions, Tao Hu answered them one by one.

　　"Although the cocoons are produced in different places and their quality is different, we have formulated relevant standards and can carry out quality control in the process." He said that in terms of product preservation, first of all, silk protein itself has a certain antibacterial effect, and Researchers will further functionalize the silk protein, such as adding some antibiotics to achieve the purpose of inhibiting bacteria.

　　Talking about whether industrial production can be realized in the future, Tao Hu said that this research is still relatively cutting-edge, and the maturity of the technology needs to be further verified. Therefore, there is still a long way to go before commercialization. The follow-up will continue to improve storage capacity and information reading speed. Conduct in-depth research.

　　Professor Liu Mengkun from the State University of New York at Stony Brook, as the co-corresponding author of the paper, also said: “Compared with traditional ultraviolet lithography and electron beam lithography, the near-field optical technology based on atomic force microscope is the in-situ processing of biomaterials at the nanometer scale. And characterization provides the possibility. In the later stage, the multi-probe parallel processing technology and fast-moving platform can be further combined, so that the silk hard disk has the potential to achieve the storage density and read and write speed of comparable commercial hard disk memory."

　　Wu Hongmei reporter Wang Chun