Atomically Precise Manufacturing

Atomically precise manufacturing (APM) is an application of nanotechnology where single molecules can be used to manufacture products at an atomic level. The technology currently has potential in highly technical fields like quantum computing, but if commercialized, would likely have a major impact across all fields of manufacturing. APM is classified as a disruptive technology, or a technology that creates large amounts of change in an existing industry.

APM is currently under development, and no easy method to manipulate individual atoms has been discovered. If advancements are made that make the technology cheap and efficient, APM could be commercialized for large-scale usage. As a disruptive technology, APM could first be marketed in niche fields such as nanomedicine and quantum computing before seeing widespread use.

Advantages of atomically precise manufacturing

Traditional manufacturing processes are mainly based on the concepts of discrete manufacturing and process manufacturing. Atomically precise manufacturing is more precise than traditional manufactoring so has the potential to allow nanoplasmonic devices in the field of quantum computing and technology, where slight errors can have major effects on the final result.

Potential Applications

Environmental

By operating at the atomic level, the efficiency of manufacturing can be greatly increased and waste can be exponentially decreased because manufacturers could have almost complete control over every aspect of the manufacturing process.

APM also has the potential to help with the widespread implementation of renewable energy sources. For example, APM has the potential to greatly increase the productivity of photovoltaic systems. Currently, photovoltaic (PV) systems are too costly for the amount of energy they produce to be used as a primary method of generating energy for large urban areas. The hope is that APM will allow PV systems to be created from cheaper, more common materials and eventually be able to phase out fossil fuels as the primary form of energy generation.

Moreover, APM could make carbon capture and storage systems more accessible.

Quantum computing

Currently, quantum computing is limited because quantum computers are affected by a wide variety of issues such as decoherence (the loss of the quantum nature of a particle) and, under these conditions, can struggle to perform basic functions correctly. In normal computers, issues of poor computing can usually be solved by providing more storage to the computer, but this is currently not a feasible option for quantum computers. The unit of storage for quantum computing is a qubit (short for a quantum bit) as opposed to a normal bit in standard computing. Researchers have to be highly conservative in their allocation of qubits because unlike a typical computer that holds hundreds of billions of bits, the best quantum computers have around 50 qubits. Since the supply of information storage is in such a scarce supply, researchers have been unable to find a way to divide qubits between error correction programs and the actual computation.

With the application of APM, researchers hope to be able to build quantum computers with larger storage modules as well as components that can maintain a coherent state indefinitely. Once these limitations have been passed, quantum computers can begin to see the commercial applications.

Room temperature superconductors

A room temperature superconductor is a substance that possesses the property of superconductivity at temperatures that could be considered 'room temperatures' (above 0°C). Room temperature superconductors have been a heavily sought technology due to the potential they hold to greatly increase energy efficiency. Usually, superconductors can only function in cryogenic environments and development on a room temperature superconductor has been unsuccessful. Report about first room temperature (15°C) superconductor H₂S + CH₄ in 2020 is not reliable ( retracted).

To create superconductors that can function at room temperatures and pressures, scientists are turning to APM to modify substances to behave differently.

Methods

Scanning tunneling microscope

A current prospective method for fabricating atomically precise (AP) goods is under development where there is a plan to use a scanning tunneling microscope (STM) to move individual atoms. Typically, an STM is used to photograph atoms and molecules, but STMs have been converted into machines with the required precision to position specific atoms. However, they are not efficient enough to be employed in large-scale manufacturing processes. The current goal is to advance the design of STMs to the point where a large group of them can fabricate goods in industrial settings.

In order to have multiple scanning tunneling microscopes operating together, an extreme level of coordination and exactness is required. A major level of precision is provided by nanopositioners (stages that position microscope samples to accuracies of within a nanometer) which allow for exact positioning on the x, y, and z axes. Once the nanopositioners are ready, the manufacturing process can begin.

The first step in the procedure is to construct a series of coordinated STM manufacturing devices that can work together efficiently and can handle the production of a large volume of product.

After this, a feedback-controlled microelectromechanical system (MEMS) will be implemented into the STMs that will allow them to operate independently of human supervision. The incorporation of the MEMS will allow the STMs to operate with anywhere from 100 to 1000 times more speed than before and with accuracy to within a nanometer, allowing for commercial usage.

Hydrogen lithography

Hydrogen lithography is a method of APM revolving specifically around data storage. A team of researchers at the University of Alberta have used hydrogen lithography to store data at a density of 1.2 petabits (150,000 gigabytes) per square inch, making this form of data storage about 100 times as dense as a Blu-Ray disc. The technology works by using an STM to move hydrogen atoms around on a silicon substrate to store information in binary as ones and zeroes. The presence of a hydrogen atom in one location signifies a one and the absence of a hydrogen atom in another location signifies a zero.

This technology represents a major leap forward from previous iterations of high-density storage devices that only functioned under ultra-specific conditions such as at subzero temperatures or in a vacuum, making them highly impractical. The new storage method that uses hydrogen lithography is stable at room temperatures and at standard atmospheric pressure. The technology is also long-lasting, and able to store information for more than half a century.

Hydrogen depassivation lithography

Hydrogen depassivation lithography (HDL) is a variant of electron beam lithography where the tip of a scanning tunneling microscope is modified to emit a cold field that fires a minuscule beam of electrons at surface covered with a film sensitive to electrons called a resist, typically made of silicon. The beam of electrons can then be manipulated to etch designs or patterns on the resist. HDL is performed in vacuums with temperatures ranging from subzero to around 250°C. Currently, HDL can be carried out in one of two forms: up to five volts of power to create atomically precise patterns and an 8-volt mode with a wider area of effect. Once a design has been made, the result is developed through the process of desorption. Desorption is the opposite of absorption where a material separates from a surface instead of being enveloped by it. In HDL, the energy released when the electrons strike the surface of the silicon resist is enough to break the chemical bond between the silicon and hydrogen atoms and the hydrogen atom ends up being desorbed.

The five-volt method has the accuracy to distances of under a nanometer but is relatively inefficient. A model that proves this method is atomically precise has been created as shown in the formula:

$i = KVe^$

where i is the value of the tunneling current in nA ( nanoamperes), K is a constant equal to 0.194, V is the bias between the tip and the sample, e is Euler's number, $T_d$ is the size of the tunneling gap of the microscope, Φ is the height of the local barrier, $m_e$is the electron mass, and $\hbar$ is Planck's constant divided by $2\pi$.

Criticisms and controversies

A variety of concerns have been raised about the potential risks the widespread use of APM could create.

Gray goo

APM could contribute to the "gray goo" doomsday scenario wherein self-replicating molecular assemblers (machines that exist at the atomic scale) uncontrollably create copies of themselves, forming a gray goo that consumes the entire planet as a resource to continue replication. However, such a scenario is extremely unrealistic. Not only would these molecular assemblers have to be purposely built for the function of creating gray goo, but developing these assemblers would take an extraordinary amount of resources. Assuming there are even people who would want to see the extinction of all life, they likely don't have the resources to accomplish this goal.

Economic

Another major issue with APM is the negative effect it could have on employment. By nature, APM is a very technologically complex medium and will require highly educated operators to be carried out. The concern is that if the economy shifts towards one that is heavily reliant on APM, the majority of the population will not have the necessary training to be successful and the poverty rate will rise.

Militarism

APM could be used to develop novel, destructive weapons and spark another global Cold War. By making destructive weapons cheaper, countries may more likely to engage in violence as well.

Surveillance and privacy

Governments and security agencies may use APM to manufacture tiny cameras and other spyware in order to spy on citizens. There are concerns about the infringement of rights that may come with this type of technology.

See also

*Drexler–Smalley debate on molecular nanotechnology
*Nanotechnology
*Molecular machine
*Molecular assembler

References

{{DEFAULTSORT:Atomically precise manufacturing
Nanotechnology
Manufacturing
Molecular machines
Emerging technologies