Nanometer Carbon materials (Carbon nanomaterials) can replace silicon in computer chips and change many other industries, but why do they linger on the edge of commercialization?
In the past 20 years, nano-carbon materials have made great breakthroughs-composed of a single substance with a size between 1 and 100 nanometers-creating a wide range of possibilities from nano-computing to intelligent medical implants.
Due to its unique strength and electrical conductivity, carbon nanomaterials may replace silicon in computer chips.
However, the commercialization of new materials is very difficult. The application of laboratory results to large-scale production is a long and dangerous process, similar to bringing new drugs to the market. Technical barriers and the high cost of laboratory time and production led to the failure of many subversive materials at an early stage.
For nano-carbon materials, conductivity and production challenges mean that computer chips based on carbon nanomaterials may be more distant than originally expected.
Start-up companies, research and development departments and university laboratories are currently developing and introducing unique nano-carbon materials one after another.
Graphene and carbon nanotubes
Due to the small size of nanomaterials, they have incomparable properties with conventional bulk materials, including high strength to weight ratio (I .e. high strength but light weight) and excellent electrical connectivity.
Carbon-based nanomaterials-especially graphene and carbon nanotubes-have shown great potential as substitutes for various industrial materials.
Graphene is a single atom thick carbon layer arranged in honeycomb structure.
Carbon nanotubes (CNT) are graphene sheets arranged in tubular structure.
Carbon nanotubes were first discovered in the early 1990 s, but graphene was not isolated by scientists at Manchester University until 2004.
For many years, graphene and carbon nanotubes have seen different development paths, although they have similar properties and applications.
Graphene is the strongest material ever measured. It has excellent strength-weight ratio, and its conductivity is close to that of superconductor, which is almost transparent. From aerospace to semiconductor to sports equipment, various industries are studying how to use graphene to improve performance.
Driven by the semiconductor industry, CNT-related research is more concentrated. IBM has invested a lot of resources to develop carbon nanotubes for computer chips.
Graphene venture capital "fever reduction"
From 2007 to 2015, the funds of graphene emerging companies increased steadily. However, the decline in transactions and funds in 2016 did not fully recover.
This decline reflects the typical loss of attraction in the development of advanced materials, and then the technology falls between breakthrough and commercialization.
Start-ups in this field are working hard to develop specific graphene products-such as batteries, medical equipment and electronic products-or are trying to effectively produce materials for general purposes.
For example, Vorbeck Materials is developing graphene-based ink and coatings for the printing electronic market. The company's graphene products can be used in wearable electronic products, RFID (radio frequency identification), sensors and other applications.
In the aspect of production, the XG Sciences who obtained the funds of Dow venture capital and Samsung Venture Capital produce and sell graphene materials. The company's proprietary technology has produced a small pile of graphene sheets called "Nanoscale" as additives for various applications.
CNT-related financing is also declining
Start-up companies are also developing carbon nanotube technology, although few companies enter this field.
Start-ups focusing on carbon nanotubes also experienced a decline in funds after 2015, which may be the same reason as the sharp decline in graphene funds. After years of research and development investment, carbon nanotubes have encountered technical obstacles. 20 years after the initial breakthrough, it has not been widely adopted.
Nantero is one of the most lucrative and ambitious CNT start-ups. The company has developed NRAM (non-volatile random access memory) using CNT, hoping it will replace DRAM (dynamic random access memory) and flash memory as the main semiconductor storage equipment.
Nantero believes that CNT technology can be used to manufacture chips with higher density than traditional semiconductor materials, greatly improving speed and memory.
Nantero has authorized its technology to Fujitsu, taking a step towards commercialization. However, technical and market barriers still need to be overcome before carbon nanotubes can be widely used in high-end computing.
Enterprises prefer to carry out internal research and development activities rather than start investment.
All major semiconductor companies are studying graphene for chips and batteries. According to CBinsights patent search engine, Samsung is the largest semiconductor manufacturer with more than 200 graphene-related patents. At the end of 2017, the company announced the development of graphene battery materials, charging 5 times faster than traditional batteries.
Carbon nanotubes have received a large amount of research and development investment from the semiconductor industry and large technology companies. IBM has more than 200 patents related to carbon nanotubes and has invested heavily in developing this material.
In the field of aerospace, graphene has shown excellent performance as an additive for carbon fiber and other composite materials. A study conducted by rensler Institute of Technology (Rensselaer Polytechnic Institute) in 2010 found that graphene has better performance than carbon nanotubes, which can make the composite materials firmer and tougher, and is not prone to defects.
Airbus has also invested in graphene-related research and has 6 graphene-related patents.
Technical barriers drag application
Graphene and carbon nanotubes are still difficult to transfer from laboratories to large-scale production and give full play to their unique material characteristics.
For example, graphene has better conductivity than silicon or copper. Combined with its strength, weight and transparency, graphene's conductivity makes it possible to replace silicon-based computer chips and improve daily electronic products.
But there is one problem-graphene is a "seamless" Semiconductor, which means that the flow of current in the material cannot be stopped. Computer chip manufacturers have to introduce "band gap" to silicon chips, which enables users to shut down devices by stopping electronic flow. The difficulty of this process is a key obstacle to commercialization.
For quite a long time, the method used to introduce band gap into graphene is inefficient, or the material has been changed, and the related superior properties have disappeared.
In April 2018, scientists led by the Catalonia Institute of Nanoscience and Nanotechnology introduced a method for growing "graphene" materials with band gaps. After graphene achieved a preliminary breakthrough in 2004, this important step of developing graphene-based chips took nearly 15 years, proving the difficulty and time required for the development of new materials.
Carbon nanotubes have band gaps, making them easy to be introduced into computer chips-but large-scale production is a crucial issue.
Manipulating billions of tiny structures in carbon nanotubes is very difficult because the orientation of nanotubes must be controlled to take advantage of their unique properties. Before being widely used, production methods need to be improved to provide uniform, defect-free carbon nanotubes.
Market Barriers: silicon is still the highlight in computing
Market Barriers to carbon nanomaterials may be more challenging than technical challenges. New materials face doubts and stagnation when trying to integrate into the existing supply chain.
Amanda Barnard2014, a physicist in charge of the Australian Federal Scientific and Industrial Research Organization, said in an interview in 2014: "We have obtained trillions of dollars in investment from global silicon chips, we will not leave this profitable field."
Before giving up continuing investment, existing participants will improve existing products or ignore new materials. The comprehensive replacement of graphene for existing materials is likely to take a long time to realize the cooperative application with silicon and other materials.
Another obstacle is standardization. A recent review of 60 graphene products by the graphene Committee shows that more than 75% of products do not have single material characteristics. If manufacturers want to effectively sell graphene, standardization needs to be introduced.
In addition, if the material will be upgraded as a substitute, the price of graphene will have to plummet. Graphene is scarce and expensive today, but it needs to be converted into materials similar to commodities, thus becoming a feasible substitute for silicon-based semiconductors.
Once this happens, entrepreneurial companies focusing on graphene may not be able to compete on prices. Smaller graphene start-ups may close down or face the acquisition of semiconductor manufacturers (such as Dow Chemical and other material companies that may want to increase the capacity of graphene).
