Nanoelectronics

Last updated

Nanoelectronics refers to the use of nanotechnology in electronic components. The term covers a diverse set of devices and materials, with the common characteristic that they are so small that inter-atomic interactions and quantum mechanical properties need to be studied extensively. Some of these candidates include: hybrid molecular/semiconductor electronics, one-dimensional nanotubes/nanowires (e.g. silicon nanowires or carbon nanotubes) or advanced molecular electronics.

Contents

Nanoelectronic devices have critical dimensions with a size range between 1 nm and 100 nm. [1] Recent silicon MOSFET (metal–oxide–semiconductor field-effect transistor, or MOS transistor) technology generations are already within this regime, including 22 nanometers CMOS (complementary MOS) nodes and succeeding 14 nm, 10 nm and 7 nm FinFET (fin field-effect transistor) generations. Nanoelectronics is sometimes considered as disruptive technology because present candidates are significantly different from traditional transistors.

Fundamental concepts

In 1965, Gordon Moore observed that silicon transistors were undergoing a continual process of scaling downward, an observation which was later codified as Moore's law. Since his observation, transistor minimum feature sizes have decreased from 10 micrometers to the 10 nm range as of 2019. Note that the technology node doesn't directly represent the minimum feature size. The field of nanoelectronics aims to enable the continued realization of this law by using new methods and materials to build electronic devices with feature sizes on the nanoscale.

Mechanical issues

The volume of an object decreases as the third power of its linear dimensions, but the surface area only decreases as its second power. This somewhat subtle and unavoidable principle has significant ramifications. For example, the power of a drill (or any other machine) is proportional to the volume, while the friction of the drill's bearings and gears is proportional to their surface area. For a normal-sized drill, the power of the device is enough to handily overcome any friction. However, scaling its length down by a factor of 1000, for example, decreases its power by 10003 (a factor of a billion) while reducing the friction by only 10002 (a factor of only a million). Proportionally it has 1000 times less power per unit friction than the original drill. If the original friction-to-power ratio was, say, 1%, that implies the smaller drill will have 10 times as much friction as power; the drill is useless.

For this reason, while super-miniature electronic integrated circuits are fully functional, the same technology cannot be used to make working mechanical devices beyond the scales where frictional forces start to exceed the available power. So even though you may see microphotographs of delicately etched silicon gears, such devices are currently little more than curiosities with limited real world applications, for example, in moving mirrors and shutters. [2] Surface tension increases in much the same way, thus magnifying the tendency for very small objects to stick together. This could possibly make any kind of "micro factory" impractical: even if robotic arms and hands could be scaled down, anything they pick up will tend to be impossible to put down. The above being said, molecular evolution has resulted in working cilia, flagella, muscle fibers and rotary motors in aqueous environments, all on the nanoscale. These machines exploit the increased frictional forces found at the micro or nanoscale. Unlike a paddle or a propeller which depends on normal frictional forces (the frictional forces perpendicular to the surface) to achieve propulsion, cilia develop motion from the exaggerated drag or laminar forces (frictional forces parallel to the surface) present at micro and nano dimensions. To build meaningful "machines" at the nanoscale, the relevant forces need to be considered. We are faced with the development and design of intrinsically pertinent machines rather than the simple reproductions of macroscopic ones.

All scaling issues therefore need to be assessed thoroughly when evaluating nanotechnology for practical applications.

Approaches

Nanofabrication

For example, electron transistors, which involve transistor operation based on a single electron. Nanoelectromechanical systems also fall under this category. Nanofabrication can be used to construct ultradense parallel arrays of nanowires, as an alternative to synthesizing nanowires individually. [3] [4] Of particular prominence in this field, Silicon nanowires are being increasingly studied towards diverse applications in nanoelectronics, energy conversion and storage. Such SiNWs can be fabricated by thermal oxidation in large quantities to yield nanowires with controllable thickness.

Nanomaterials electronics

Besides being small and allowing more transistors to be packed into a single chip, the uniform and symmetrical structure of nanowires and/or nanotubes allows a higher electron mobility (faster electron movement in the material), a higher dielectric constant (faster frequency), and a symmetrical electron/hole characteristic. [5]

Also, nanoparticles can be used as quantum dots.

Molecular electronics

Single-molecule electronic devices are extensively researched. These schemes would make heavy use of molecular self-assembly, designing the device components to construct a larger structure or even a complete system on their own. This can be very useful for reconfigurable computing, and may even completely replace present FPGA technology.

Molecular electronics [6] is a technology under development brings hope for future atomic-scale electronic systems. A promising application of molecular electronics was proposed by the IBM researcher Ari Aviram and the theoretical chemist Mark Ratner in their 1974 and 1988 papers Molecules for Memory, Logic and Amplification (see unimolecular rectifier). [7] [8]

Many nanowire structures have been studied as candidates for interconnecting nanoelectronic devices: nanotubes of carbon and other materials, metal atom chaines, cumulene or polyyne carbon atom chains, [9] and many polymers such as polythiophenes.

Other approaches

Nanoionics studies the transport of ions rather than electrons in nanoscale systems.

Nanophotonics studies the behavior of light on the nanoscale, and has the goal of developing devices that take advantage of this behavior.

Nanoelectronic devices

Current high-technology production processes are based on traditional top down strategies, where nanotechnology has already been introduced silently. The critical length scale of integrated circuits is already at the nanoscale (50  nm and below) regarding the gate length of transistors in CPUs or DRAM devices.

Computers

Simulation result for formation of inversion channel (electron density) and attainment of threshold voltage (IV) in a nanowire MOSFET. Note that the threshold voltage for this device lies around 0.45V. Threshold formation nowatermark.gif
Simulation result for formation of inversion channel (electron density) and attainment of threshold voltage (IV) in a nanowire MOSFET. Note that the threshold voltage for this device lies around 0.45V.

Nanoelectronics holds the promise of making computer processors more powerful than are possible with conventional semiconductor fabrication techniques. A number of approaches are currently being researched, including new forms of nanolithography, as well as the use of nanomaterials such as nanowires or small molecules in place of traditional CMOS components. Field effect transistors have been made using both semiconducting carbon nanotubes [10] and with heterostructured semiconductor nanowires (SiNWs). [11]

Memory storage

Electronic memory designs in the past have largely relied on the formation of transistors. However, research into crossbar switch based electronics have offered an alternative using reconfigurable interconnections between vertical and horizontal wiring arrays to create ultra high density memories. Two leaders in this area are Nantero which has developed a carbon nanotube based crossbar memory called Nano-RAM and Hewlett-Packard which has proposed the use of memristor material as a future replacement of Flash memory.[ citation needed ]

An example of such novel devices is based on spintronics. The dependence of the resistance of a material (due to the spin of the electrons) on an external field is called magnetoresistance. This effect can be significantly amplified (GMR - Giant Magneto-Resistance) for nanosized objects, for example when two ferromagnetic layers are separated by a nonmagnetic layer, which is several nanometers thick (e.g. Co-Cu-Co). The GMR effect has led to a strong increase in the data storage density of hard disks and made the gigabyte range possible. The so-called tunneling magnetoresistance (TMR) is very similar to GMR and based on the spin dependent tunneling of electrons through adjacent ferromagnetic layers. Both GMR and TMR effects can be used to create a non-volatile main memory for computers, such as the so-called magnetic random access memory or MRAM.[ citation needed ]

Novel optoelectronic devices

In the modern communication technology traditional analog electrical devices are increasingly replaced by optical or optoelectronic devices due to their enormous bandwidth and capacity, respectively. Two promising examples are photonic crystals and quantum dots.[ citation needed ] Photonic crystals are materials with a periodic variation in the refractive index with a lattice constant that is half the wavelength of the light used. They offer a selectable band gap for the propagation of a certain wavelength, thus they resemble a semiconductor, but for light or photons instead of electrons. Quantum dots are nanoscaled objects, which can be used, among many other things, for the construction of lasers. The advantage of a quantum dot laser over the traditional semiconductor laser is that their emitted wavelength depends on the diameter of the dot. Quantum dot lasers are cheaper and offer a higher beam quality than conventional laser diodes.

Fullerene Nanogears - GPN-2000-001535.jpg

Displays

The production of displays with low energy consumption might be accomplished using carbon nanotubes (CNT) and/or Silicon nanowires. Such nanostructures are electrically conductive and due to their small diameter of several nanometers, they can be used as field emitters with extremely high efficiency for field emission displays (FED). The principle of operation resembles that of the cathode ray tube, but on a much smaller length scale.[ citation needed ]

Quantum computers

Entirely new approaches for computing exploit the laws of quantum mechanics for novel quantum computers, which enable the use of fast quantum algorithms. The Quantum computer has quantum bit memory space termed "Qubit" for several computations at the same time. In nanoelectronic devices, the qubit is encoded by the quantum state of one or more electrons spin. The spin are confined by either a semiconductor quantum dot or a dopant. [12]

Radios

Nanoradios have been developed structured around carbon nanotubes. [13]

Energy production

Research is ongoing to use nanowires and other nanostructured materials with the hope to create cheaper and more efficient solar cells than are possible with conventional planar silicon solar cells. [14] It is believed that the invention of more efficient solar energy would have a great effect on satisfying global energy needs.

There is also research into energy production for devices that would operate in vivo , called bio-nano generators. A bio-nano generator is a nanoscale electrochemical device, like a fuel cell or galvanic cell, but drawing power from blood glucose in a living body, much the same as how the body generates energy from food. To achieve the effect, an enzyme is used that is capable of stripping glucose of its electrons, freeing them for use in electrical devices. The average person's body could, theoretically, generate 100 watts of electricity (about 2000 food calories per day) using a bio-nano generator. [15] However, this estimate is only true if all food was converted to electricity, and the human body needs some energy consistently, so possible power generated is likely much lower. The electricity generated by such a device could power devices embedded in the body (such as pacemakers), or sugar-fed nanorobots. Much of the research done on bio-nano generators is still experimental, with Panasonic's Nanotechnology Research Laboratory among those at the forefront.

Medical diagnostics

There is great interest in constructing nanoelectronic devices [16] [17] [18] that could detect the concentrations of biomolecules in real time for use as medical diagnostics, [19] thus falling into the category of nanomedicine. [20] A parallel line of research seeks to create nanoelectronic devices which could interact with single cells for use in basic biological research. [21] These devices are called nanosensors. Such miniaturization on nanoelectronics towards in vivo proteomic sensing should enable new approaches for health monitoring, surveillance, and defense technology. [22] [23] [24]

Related Research Articles

<span class="mw-page-title-main">Nanotechnology</span> Technology with features near one nanometer

Nanotechnology is the manipulation of matter with at least one dimension sized from 1 to 100 nanometers (nm). At this scale, commonly known as the nanoscale, surface area and quantum mechanical effects become important in describing properties of matter. This definition of nanotechnology includes all types of research and technologies that deal with these special properties. It is common to see the plural form "nanotechnologies" as well as "nanoscale technologies" to refer to research and applications whose common trait is scale. An earlier understanding of nanotechnology referred to the particular technological goal of precisely manipulating atoms and molecules for fabricating macroscale products, now referred to as molecular nanotechnology.

Molecular electronics is the study and application of molecular building blocks for the fabrication of electronic components. It is an interdisciplinary area that spans physics, chemistry, and materials science. The unifying feature is use of molecular building blocks to fabricate electronic components. Due to the prospect of size reduction in electronics offered by molecular-level control of properties, molecular electronics has generated much excitement. It provides a potential means to extend Moore's Law beyond the foreseen limits of small-scale conventional silicon integrated circuits.

A nanowire is a nanostructure in the form of a wire with the diameter of the order of a nanometre (10−9 m). More generally, nanowires can be defined as structures that have a thickness or diameter constrained to tens of nanometers or less and an unconstrained length. At these scales, quantum mechanical effects are important—which coined the term "quantum wires".

<span class="mw-page-title-main">Molecular-beam epitaxy</span> Crystal growth process

Molecular-beam epitaxy (MBE) is an epitaxy method for thin-film deposition of single crystals. MBE is widely used in the manufacture of semiconductor devices, including transistors. MBE is used to make diodes and MOSFETs at microwave frequencies, and to manufacture the lasers used to read optical discs.

<span class="mw-page-title-main">Nanoelectromechanical systems</span> Class of devices for nanoscale functionality

Nanoelectromechanical systems (NEMS) are a class of devices integrating electrical and mechanical functionality on the nanoscale. NEMS form the next logical miniaturization step from so-called microelectromechanical systems, or MEMS devices. NEMS typically integrate transistor-like nanoelectronics with mechanical actuators, pumps, or motors, and may thereby form physical, biological, and chemical sensors. The name derives from typical device dimensions in the nanometer range, leading to low mass, high mechanical resonance frequencies, potentially large quantum mechanical effects such as zero point motion, and a high surface-to-volume ratio useful for surface-based sensing mechanisms. Applications include accelerometers and sensors to detect chemical substances in the air.

Hybrid solar cells combine advantages of both organic and inorganic semiconductors. Hybrid photovoltaics have organic materials that consist of conjugated polymers that absorb light as the donor and transport holes. Inorganic materials are used as the acceptor and electron transport. These devices have a potential for low-cost by roll-to-roll processing and scalable solar power conversion.

<span class="mw-page-title-main">Nanochemistry</span> Combination of chemistry and nanoscience

Nanochemistry is an emerging sub-discipline of the chemical and material sciences that deals with the development of new methods for creating nanoscale materials. The term "nanochemistry" was first used by Ozin in 1992 as 'the uses of chemical synthesis to reproducibly afford nanomaterials from the atom "up", contrary to the nanoengineering and nanophysics approach that operates from the bulk "down"'. Nanochemistry focuses on solid-state chemistry that emphasizes synthesis of building blocks that are dependent on size, surface, shape, and defect properties, rather than the actual production of matter. Atomic and molecular properties mainly deal with the degrees of freedom of atoms in the periodic table. However, nanochemistry introduced other degrees of freedom that controls material's behaviors by transformation into solutions. Nanoscale objects exhibit novel material properties, largely as a consequence of their finite small size. Several chemical modifications on nanometer-scaled structures approve size dependent effects.

<span class="mw-page-title-main">Charles M. Lieber</span> American chemist (born 1959)

Charles M. Lieber is an American chemist, inventor, nanotechnologist, and writer. In 2011, Lieber was named the leading chemist in the world for the decade 2000–2010 by Thomson Reuters, based on the impact of his scientific publications. He is known for his contributions to the synthesis, assembly and characterization of nanoscale materials and nanodevices, the application of nanoelectronic devices in biology, and as a mentor to numerous leaders in nanoscience.

The history of nanotechnology traces the development of the concepts and experimental work falling under the broad category of nanotechnology. Although nanotechnology is a relatively recent development in scientific research, the development of its central concepts happened over a longer period of time. The emergence of nanotechnology in the 1980s was caused by the convergence of experimental advances such as the invention of the scanning tunneling microscope in 1981 and the discovery of fullerenes in 1985, with the elucidation and popularization of a conceptual framework for the goals of nanotechnology beginning with the 1986 publication of the book Engines of Creation. The field was subject to growing public awareness and controversy in the early 2000s, with prominent debates about both its potential implications as well as the feasibility of the applications envisioned by advocates of molecular nanotechnology, and with governments moving to promote and fund research into nanotechnology. The early 2000s also saw the beginnings of commercial applications of nanotechnology, although these were limited to bulk applications of nanomaterials rather than the transformative applications envisioned by the field.

<span class="mw-page-title-main">Multigate device</span> MOS field-effect transistor with more than one gate

A multigate device, multi-gate MOSFET or multi-gate field-effect transistor (MuGFET) refers to a metal–oxide–semiconductor field-effect transistor (MOSFET) that has more than one gate on a single transistor. The multiple gates may be controlled by a single gate electrode, wherein the multiple gate surfaces act electrically as a single gate, or by independent gate electrodes. A multigate device employing independent gate electrodes is sometimes called a multiple-independent-gate field-effect transistor (MIGFET). The most widely used multi-gate devices are the FinFET and the GAAFET, which are non-planar transistors, or 3D transistors.

Nanocircuits are electrical circuits operating on the nanometer scale where quantum mechanical effects become important. One nanometer is equal to 10−9 meters or a row of 10 hydrogen atoms. With such progressively smaller circuits, more can be fitted on a computer chip. This allows faster and more complex functions using less power. Nanocircuits are composed of three different fundamental components. These are transistors, interconnections, and architecture, all fabricated on the nanometer scale.

The following outline is provided as an overview of and topical guide to nanotechnology:

A carbon nanotube field-effect transistor (CNTFET) is a field-effect transistor that utilizes a single carbon nanotube (CNT) or an array of carbon nanotubes as the channel material, instead of bulk silicon, as in the traditional MOSFET structure. There have been major developments since CNTFETs were first demonstrated in 1998.

<span class="mw-page-title-main">Supriyo Datta</span> Indian-American scientist and educator

Supriyo Datta is an Indian–American researcher and author. A leading figure in the modeling and understanding of nano-scale electronic conduction, he has been called "one of the most original thinkers in the field of nanoscale electronics."

The applications of nanotechnology, commonly incorporate industrial, medicinal, and energy uses. These include more durable construction materials, therapeutic drug delivery, and higher density hydrogen fuel cells that are environmentally friendly. Being that nanoparticles and nanodevices are highly versatile through modification of their physiochemical properties, they have found uses in nanoscale electronics, cancer treatments, vaccines, hydrogen fuel cells, and nanographene batteries.

<span class="mw-page-title-main">Mark S. Lundstrom</span>

Mark S. Lundstrom is an American electrical engineering researcher, educator, and author. He is known for contributions to the theory, modeling, and understanding of semiconductor devices, especially nanoscale transistors, and as the creator of the nanoHUB, a major online resource for nanotechnology. Lundstrom is Don and Carol Scifres Distinguished Professor of Electrical and Computer Engineering and in 2020 served as Acting Dean of the College of Engineering at Purdue University, in West Lafayette, Indiana.

In nanotechnology, carbon nanotube interconnects refer to the proposed use of carbon nanotubes in the interconnects between the elements of an integrated circuit. Carbon nanotubes (CNTs) can be thought of as single atomic layer graphite sheets rolled up to form seamless cylinders. Depending on the direction on which they are rolled, CNTs can be semiconducting or metallic. Metallic carbon nanotubes have been identified as a possible interconnect material for the future technology generations and to replace copper interconnects. Electron transport can go over long nanotube lengths, 1 μm, enabling CNTs to carry very high currents (i.e. up to a current density of 109 A∙cm−2) with essentially no heating due to nearly one dimensional electronic structure. Despite the current saturation in CNTs at high fields, the mitigation of such effects is possible due to encapsulated nanowires.

<span class="mw-page-title-main">Silicon nanowire</span>

Silicon nanowires, also referred to as SiNWs, are a type of semiconductor nanowire most often formed from a silicon precursor by etching of a solid or through catalyzed growth from a vapor or liquid phase. Such nanowires have promising applications in lithium-ion batteries, thermoelectrics and sensors. Initial synthesis of SiNWs is often accompanied by thermal oxidation steps to yield structures of accurately tailored size and morphology.

Jean-Pierre Leburton is the Gregory E. Stillman Professor of Electrical and Computer Engineering and professor of Physics at the University of Illinois Urbana–Champaign. He is also a full-time faculty member in the Nanoelectronics and Nanomaterials group of the Beckman Institute for Advanced Science and Technology. He is known for his work on semiconductor theory and simulation, and on nanoscale quantum devices including quantum wires, quantum dots, and quantum wells. He studies and develops nanoscale materials with potential electronic and biological applications.

This glossary of nanotechnology is a list of definitions of terms and concepts relevant to nanotechnology, its sub-disciplines, and related fields.

References

  1. Beaumont, Steven P. (September 1996). "III–V Nanoelectronics". Microelectronic Engineering. 32 (1): 283–295. doi:10.1016/0167-9317(95)00367-3. ISSN   0167-9317.
  2. "MEMS Overview" . Retrieved 2009-06-06.
  3. Melosh, N.; Boukai, Abram; Diana, Frederic; Gerardot, Brian; Badolato, Antonio; Petroff, Pierre; Heath, James R. (2003). "Ultrahigh density nanowire lattices and circuits". Science . 300 (5616): 112–5. Bibcode:2003Sci...300..112M. doi: 10.1126/science.1081940 . PMID   12637672. S2CID   6434777.
  4. Das, S.; Gates, A.J.; Abdu, H.A.; Rose, G.S.; Picconatto, C.A.; Ellenbogen, J.C. (2007). "Designs for Ultra-Tiny, Special-Purpose Nanoelectronic Circuits". IEEE Transactions on Circuits and Systems I. 54 (11): 11. doi:10.1109/TCSI.2007.907864. S2CID   13575385.
  5. Goicoechea, J.; Zamarreñoa, C.R.; Matiasa, I.R.; Arregui, F.J. (2007). "Minimizing the photobleaching of self-assembled multilayers for sensor applications". Sensors and Actuators B: Chemical. 126 (1): 41–47. doi:10.1016/j.snb.2006.10.037.
  6. Petty, M.C.; Bryce, M.R.; Bloor, D. (1995). An Introduction to Molecular Electronics. London: Edward Arnold. ISBN   978-0-19-521156-6.
  7. Aviram, A.; Ratner, M. A. (1974). "Molecular Rectifier". Chemical Physics Letters . 29 (2): 277–283. Bibcode:1974CPL....29..277A. doi:10.1016/0009-2614(74)85031-1.
  8. Aviram, A. (1988). "Molecules for memory, logic, and amplification". Journal of the American Chemical Society . 110 (17): 5687–5692. doi:10.1021/ja00225a017.
  9. Bryce, Martin R. (2021). "A review of functional linear carbon chains (oligoynes, polyynes, cumulenes) and their applications as molecular wires in molecular electronics and optoelectronics". J. Mater. Chem. C. 9 (33): 10524–10546. doi: 10.1039/d1tc01406d . ISSN   2050-7526. S2CID   235456429.
  10. Postma, Henk W. Ch.; Teepen, Tijs; Yao, Zhen; Grifoni, Milena; Dekker, Cees (2001). "Carbon nanotube single-electron transistors at room temperature". Science . 293 (5527): 76–79. Bibcode:2001Sci...293...76P. doi:10.1126/science.1061797. PMID   11441175. S2CID   10977413.
  11. Xiang, Jie; Lu, Wei; Hu, Yongjie; Wu, Yue; Yan Hao; Lieber, Charles M. (2006). "Ge/Si nanowire heterostructures as highperformance field-effect transistors". Nature . 441 (7092): 489–493. Bibcode:2006Natur.441..489X. doi:10.1038/nature04796. PMID   16724062. S2CID   4408636.
  12. Achilli, Simona; Le, Nguyen H.; Fratesi, Guido; Manini, Nicola; Onida, Giovanni; Turchetti, Marco; Ferrari, Giorgio; Shinada, Takahiro; Tanii, Takashi; Prati, Enrico (February 2021). "Position-Controlled Functionalization of Vacancies in Silicon by Single-Ion Implanted Germanium Atoms". Advanced Functional Materials. 31 (21): 2011175. arXiv: 2102.01390v2 . doi:10.1002/adfm.202011175. S2CID   231749540.
  13. Jensen, K.; Weldon, J.; Garcia, H.; Zettl A. (2007). "Nanotube Radio". Nano Lett. 7 (11): 3508–3511. Bibcode:2007NanoL...7.3508J. doi:10.1021/nl0721113. PMID   17973438.
  14. Tian, Bozhi; Zheng, Xiaolin; Kempa, Thomas J.; Fang, Ying; Yu, Nanfang; Yu, Guihua; Huang, Jinlin; Lieber, Charles M. (2007). "Coaxial silicon nanowires as solar cells and nanoelectronic power sources". Nature . 449 (7164): 885–889. Bibcode:2007Natur.449..885T. doi:10.1038/nature06181. PMID   17943126. S2CID   2688078.
  15. "Power from blood could lead to 'human batteries'". Sydney Morning Herald. August 4, 2003. Retrieved 2008-10-08.
  16. LaVan, D.A.; McGuire, Terry & Langer, Robert (2003). "Small-scale systems for in vivo drug delivery". Nat. Biotechnol. 21 (10): 1184–1191. doi:10.1038/nbt876. PMID   14520404. S2CID   1490060.
  17. Grace, D. (2008). "Special Feature: Emerging Technologies". Medical Product Manufacturing News. 12: 22–23. Archived from the original on 2008-06-12.
  18. Saito, S. (1997). "Carbon Nanotubes for Next-Generation Electronics Devices". Science . 278 (5335): 77–78. doi:10.1126/science.278.5335.77. S2CID   137586409.
  19. Cavalcanti, A.; Shirinzadeh, B.; Freitas Jr, Robert A. & Hogg, Tad (2008). "Nanorobot architecture for medical target identification". Nanotechnology. 19 (1): 015103(15pp). Bibcode:2008Nanot..19a5103C. doi:10.1088/0957-4484/19/01/015103. S2CID   15557853.
  20. Cheng, Mark Ming-Cheng; Cuda, Giovanni; Bunimovich, Yuri L; Gaspari, Marco; Heath, James R; Hill, Haley D; Mirkin,Chad A; Nijdam, A Jasper; Terracciano, Rosa; Thundat, Thomas; Ferrari, Mauro (2006). "Nanotechnologies for biomolecular detection and medical diagnostics". Current Opinion in Chemical Biology . 10 (1): 11–19. doi:10.1016/j.cbpa.2006.01.006. PMID   16418011.
  21. Patolsky, F.; Timko, B.P.; Yu, G.; Fang, Y.; Greytak, A.B.; Zheng, G.; Lieber, C.M. (2006). "Detection, stimulation, and inhibition of neuronal signals with high-density nanowire transistor arrays". Science . 313 (5790): 1100–1104. Bibcode:2006Sci...313.1100P. doi:10.1126/science.1128640. PMID   16931757. S2CID   3178344.
  22. Frist, W.H. (2005). "Health care in the 21st century". N. Engl. J. Med. 352 (3): 267–272. doi: 10.1056/NEJMsa045011 . PMID   15659726.
  23. Cavalcanti, A.; Shirinzadeh, B.; Zhang, M. & Kretly, L.C. (2008). "Nanorobot Hardware Architecture for Medical Defense" (PDF). Sensors. 8 (5): 2932–2958. Bibcode:2008Senso...8.2932C. doi: 10.3390/s8052932 . PMC   3675524 . PMID   27879858.
  24. Couvreur, P. & Vauthier, C. (2006). "Nanotechnology: intelligent design to treat complex disease". Pharm. Res. 23 (7): 1417–1450. doi: 10.1007/s11095-006-0284-8 . PMID   16779701. S2CID   1520698.

Further reading