About the functional applications of diamond

 Material is one of the three pillars of modern civilization, and new material is the foundation and forerunner of new technological revolution. Throughout the history of human use of materials, we can clearly see that every discovery and application of new materials has raised human's ability to transform nature to a new level, and every major breakthrough in materials science will cause a revolution in production technology, bringing great changes to social production and people's life.

　　In the Harvard study, a 100-nm diamond particle was implanted into a human cell and then illuminated with a green laser. Because the laser changes the spin state of the electrons in the impurity, the green laser passes through the nano-diamond particles and becomes a red laser. The degree to which the laser changes color can be used to measure temperature changes in human cells.

This kind of high-precision temperature difference measurement technology based on nano-diamond particles can help doctors distinguish carcinogenic cells in human body and make medical diagnosis in time in the medical field. Therefore, nano-diamond material has a broader application prospect.

1.2 nano-diamond is used to improve the chemotherapy effect of leukemia

Daunorubicin(Daunorubicin) is a commonly used treatment for leukemia. The drug slows or stops the growth of cancer cells and causes most cancer cells to die. However, it can also make leukaemia cells resistant to the drug, and when the drug is given to the leukaemia cells it actively excretes chemotherapeutics, including daorubicin.

Scientists at the National University of Singapore and the University of California turned to nanodiamonds as a topic to solve medicinal properties, in order to investigate the biological mechanisms by which nanodiamonds might overcome drug resistance.

The scientists bonded daorubicin to the surface of the nanodiamond, which was then introduced into leukemia cells. Nanodiamonds were found to transport drugs into cancer cells without being excreted. Due to their non-invasive size and unique surface properties, nanodiamonds can be easily released without clogging blood vessels.

Dr Zhou, who worked on the study, said: "The use of nanodiamonds provides an ideal biocompatible complex and is an ideal therapeutic transport to enhance the therapeutic effect." One of the current goals is to determine how well drugs will be transported by nanodiamonds to specific disease models, which will benefit patients in the future.

Further systematic research and safety evaluation of nano-diamond will be expected to realize its full use, and it is hoped that the research work can be applied to the clinical treatment of leukemia, without the situation of daorubicin treatment.

The U.S. Food and Drug Administration (FDA) has approved the Abraxane study, which will help accelerate the development of novel nanotherapeutic drugs and imaging techniques to treat cancer.

1.3 Use nano diamond to deliver chemotherapeutic drugs for brain tumor

Researchers at the University of California at Jonson Comprehensive Cancer Center have developed an innovative drug delivery system that uses tiny particles of nano-diamond to deliver chemotherapy drugs to brain tumors. The new treatment effectively kills cancer cells with minimal side effects compared to existing treatments

Adriamycin is a common chemotherapy agent. When injected directly into the tumor, it acts as a drug to treat the tumor. Dean Holjan of the University of California School of Dentistry created a compound, Nd-DOX, by attaching molecules to nanodiamond surfaces.

It was found that tumor ND-DOX water remained stable over doxorubicin alone, indicating that doxorubicin attached to the nanodiamond entered the tumor and remained there for a longer time. It was also found that ND-DOX increased the death of cancer cells and decreased the viability of glioma cells.

The first study showed that ND-DOX transported limited doses of doxorubicin, scattered outside the tumor. This mode of transport reduces toxic side effects and ensures that the drug stays in the tumor longer, increasing its effectiveness in killing the tumor without affecting surrounding tissue.

Applications in microelectromechanical systems

Resistivity and thermal conductivity of diamond is the highest of all material, using the characteristic of the diamond, the electronic deposition nano diamond film on the surface of material, can greatly reduce component parts for heat dissipation in the original size, this not only solves the problem of thermal conductivity, but also provides the possibility of the production of very large scale integrated circuit. The membrane also acts as an insulating protection for conductors, avoiding interference between components.

The ultranano Diamond (UNCD) films developed by Argonne National Laboratory and the related products of ADT(Advanced Diamond Technologies Inc.) can be used to fabricate MEMS/NEMS devices. Examples include rf oscillators, accelerometers, AFM probes, micromotors.

　　3 application of optical properties

3.1 Missile infrared window

ZnS and ZnSe are commonly used infrared window materials. Although these two kinds of materials have good infrared transmittance, their physical characteristics are fragile and easy to be damaged. In military and unconventional applications, the requirements for infrared Windows are very strict. These devices often work in very harsh conditions, such as infrared Windows for missiles, which not only operate at high speed after a missile is launched, but also have to withstand wind, rain and snow. Diamond film is a kind of high quality surface material, diamond has infrared antireflection property, and diamond film is also a good antireflection film material for infrared window. In addition, diamond's high thermal conductivity, wear resistance and other characteristics can also well protect the infrared window from external impact. Therefore, gold-plated corundum film on the surface of infrared window completely solves various problems of infrared window application in military aerospace field.

Lockheed Missiles and Space Company, USA, has used low-pressure gas-phase synthesis diamond film to create Windows for atmospheric kinetic energy weapon missile interceptors. Double-sided gold-plated corundum film on silicon wafer can increase light transmittance by 26%. The Windows can withstand harsh high-speed flight without window launch due to flight-optical effects.

3.2 Novel diamond lens for optical data storage

Since 1985, compact disks and CDS have become the standard storage medium for music, digital cameras, computer data and games. As the storage capacity of the disk continues to increase, the future generation of optical media will need to have high storage capacity. This trend is already evident in the DVD and its successor, blu-Ray discs. Diamond lens is the core component of the next generation of storage technology, its storage capacity will be more than 1TB(1000GB) per disk.

The key to increasing the density of data storage is to be able to create small lenses that work with short waves. The storage capacity of the disk is increased through technical improvements, i.e. by reducing the wavelength of the laser reader and increasing the digital grating (NA) of the focusing lens. It is necessary to obtain a high NA value, and the material used is very important. In use, it is necessary to have a high refractive index and transparency, and diamond is the first choice material suitable for these conditions.

The synthetic diamond obtained by chemical treatment of fenin deposition by Element six is an ideal optical material to meet the needs. Lens-makers have made an important technological breakthrough that will allow lenses to store vast amounts of data for commercial use. This is also a new development of diamond processing technology in the microscopic field, and also a demonstration of diamond's versatility.

3.3 For stealth materials

In recent years, with the development of science and technology, a variety of detection methods are more and more advanced, for example, electromagnetic radar can detect aircraft, infrared detectors can also find radiating infrared objects. At present, in order to meet the needs of modern war and improve the strength in military confrontation, the world also takes stealth technology as an important research object, and stealth materials play an important role in stealth technology. Using a small amount of nano-diamond suspended in the coating, spraying it on aircraft, tanks, missiles, warships, can play a stealth anticorrosion role.

Why ultrafine particles, especially nanoparticles, have stealth effect on infrared and electromagnetic waves? There are two main reasons: on the one hand, due to the size of nanoparticles is far less than infrared and radar wavelength, so the material to the wavelength of the nanoparticles through rate is better than the conventional materials, this greatly reduces the reflectivity of the wave, makes infrared detector and radar receives the reflected signal is very weak, so, reach the role of stealth; On the other hand, the surface area of nano-particle material is 3-4 orders of magnitude larger than that of conventional coarse powder, and the absorption rate of infrared light and electromagnetic wave is much larger than that of conventional material, which makes the reflected signal intensity of infrared detector and radar greatly reduced, so it is difficult to find the detected target, playing a stealth role. At present, although stealth materials have broad application prospects in many aspects, most of the stealth materials that really play a role are used in aerospace and military components. There is a requirement for the material in the sky is light weight, in this respect, nanomaterials have advantages, especially by light elements composed of nanomaterials in aviation stealth is widely used.

4 Applications in detectors and sensors

Anna Dabrowski, a CERN scientist in charge of the CMS experiment, said: "Our CMS lab relies on the stability of synthetic diamonds to monitor the LHC beams and the particles produced during the collisions. The stability of this diamond-based system is important for protecting sensors with 66 million channels of pixel tracking. (NOVEL MATERIAS:Synthetic diamond offers much more than heat sinking)

In addition to particle detection, applications in this area include:

Micro magnetometers are developed using single crystal diamonds with nitrogen vacancy centers and are sensing by the strength and direction of the magnetic field.

A highly reversible electrochemical sensor is produced by using the inert and boron-doped conductivity of diamond.

Boron-doped diamond in bipolar electrochemical cell is used to replace corrosive liquid, reduce harmful chemicals, and realize the production of environmental protection battery.

Application in the field of acoustics

5.1 Used for making high-fidelity acoustic devices

Diamond has the highest sound transmission velocity (C=18.5km/s) and moderate internal damping factor. The vibration film prepared with diamond film has excellent high-frequency response characteristics, and the HRF value of the material increases with the increase of the sound transmission velocity, up to 63K Hz. The signal-to-noise ratio also increases with the increase of sound transmission speed, and a high signal-to-noise ratio can produce a clear sound. Due to the High HRF of DF and DLC, DF and DLC are the most ideal materials for middle and High treble diaphragm, which can be used to manufacture high-fidility (hi-Fi) acoustic devices.

Polycrystalline diamond coated ceramic diaphragm has been used as high frequency diaphragm for high-end stereo speakers. DLC coated vibration film has been close to commercialization in the world, while DF vibration film is still far from commercialization.

5.2 The space probe Voyager 1 left the solar system with a diamond phonograph needle

The Voyager 1 probe, launched in 1977, has arrived at the edge of the solar system, NASA's Jet Propulsion Laboratory has announced.

The unique feature of the spacecraft, which is on a mission to find cosmic civilization, is that it carries a 12-inch-thick copper disc record with a gold-plated surface and a diamond phonograph needle. Diamond has high Young's modulus and elastic modulus, which is convenient for high frequency acoustic wave transmission with high fidelity. It is the most ideal material for high frequency diaphragm of loudspeaker.

A "letter" to an extraterrestrial civilization extended its useful life to over a billion years thanks to its unique diamond phonograph needle device. After leaving the solar system, Voyager 1 will also carry earthlings' greetings toward the center of the Milky Way at 17 kilometers per second.

5.3 As an ideal material for rf micromotors and SAW devices

UNCD has the highest sound speed, low power consumption (high Q value), low frequency temperature coefficient and linear frequency response at high frequency/power, making it an ideal material for RF microcomputer electrical components in the GHz band. UNCD is used to directly integrate rf filters and switches with performance microelectronics to achieve enhanced performance and greatly reduce device size.

The surface acoustic velocity of diamond film can reach 9000 ~ 0000m/s, which is the highest among all materials at present. Therefore, the highest frequency SAW devices can be made with diamond film. In addition, the high thermal conductivity of diamond enables SAW devices to withstand higher power. Japan Sumitomo Electric co., Ltd. is a world leader in the manufacture of silicon fund corundum film substrate SAW devices. In 2002, 5GHz was achieved.

6 For magnetic recording system

Firstly, the application of nano-diamond in magnetic field coating of magnetic tape and disk is as wear reducing additive and physical denaturating agent. Secondly, the stability of magnetic recording can be improved by adding it to electrochemical composite coating.

Magnetic nanoparticles have the characteristics of single domain structure and high coercivity due to their small size. The signal-to-noise ratio and image quality can be improved by making magnetic recording materials with them. The size of the magnetic particle as a unit of magnetic recording must meet the following requirements:

(1) The length of particles should be much smaller than the recording wavelength;

(2) The particle width should be much smaller than the recording depth;

(3) There are as many magnetic particles as possible in a unit of recording volume.

The addition of nano-diamond to the ferromagnetic layer can significantly reduce the magnetic domain (ferromagnetic particles), that is, the density of the recording can be significantly increased.

When nano diamond is introduced into the special film of clean magnetic head, its wear resistance increases obviously.

The soft magnetic information carrier containing nano-diamond has the following advantages: the wear of magnetic carrier layer is reduced, friction is reduced and operation stability is improved.

Compared with pure CoP coating, cop-nano-diamond soft magnetic amorphous film shows that the microhardness increases by 30%, wear resistance increases by 3.5 times, friction coefficient decreases by 28.6%, and the service life of magnetic head iron core increases by 1 times.