Nanotechnology is a rapidly growing field that touches pretty much every STEM area. In a new world where technology is evolving at a pace much higher than any point of time in recorded history, nanoengineering is pushing the boundaries of conventional technological practices. It is helping engineers and researchers all over the world to not only improve the current line of products and technologies, but to develop entirely novel functionalities, achieved by the bottom-up approach of construction.
Nanotechnology picked up rapidly after the invention of scanning tunneling microscope (STM) in 1980 by Gerd Binnig and Heinrich Rohrer at IBM Zurich, which also earned them the Nobel prize in physics in 1986. The development of STM was a precursor to the development of atomic force microscope (AFM) which ultimately allowed scientists to see the materials at unprecedentedly small scales. We have come a long way since the 1980s and the time is perfect to review some of the key nanotechnology developments in STEM fields.
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Medically assisted reproduction
Reproductive medicine is in pursuit of alternatives to assist couples looking to achieve pregnancy and preserve fertility. It also aims to diagnose and treat diseases that are impairing the normal operation of the reproductive tract. ART or assisted reproductive technology is backed by nanotechnology to achieve this feat by non-invasive detection, diagnosis and treatment of infertility related disorders. Development of nanobiosensors which are capable of identifying antigens, nucleic acids, antigens, nitrogen species and reactive oxygen are being researched and employed for greater speed and more sensitivity. These nanobiosensors are a part of a more complex lab-on-a-chip tool which requires minimal volumes of analyte and precursors and have the potential to replace conventional bulky and expensive detection systems. Few examples include functionalization of zinc oxide nanorods and gold nanoparticles, iron oxide nanoparticles, silica coated gold nanoparticles with cadmium sulphide quantum dots along with anti-CA125 antibodies for the detection of ovarian cancer. Similar biosensors using anti-PSA antibodies functionalized on gold can detect PSA antigen for prostate cancer. Apart from that, for in vitro maturation, the addition of antioxidants is a prerequisite but these conventional molecules may not exert their function with high efficiency due to their inefficiency in, in-vitro environment, making utilization of nanomaterials an essential.
Wound healing, in general, is a natural and well-structured process. However, several factors disturb the sequence of wound healing. Numerous nanotechnology-based drug delivery systems such as the use of silver, gold, copper, titanium dioxide and zinc oxide nanoparticles against the strains of B. subtilis, E. coli and S. aureus etc. are being commercially employed. Biocompatible scaffolds combined with bioactive molecules regenerate and repair damaged skin tissues. Biomaterials such as chitosan, collagen and polylactic acid have been tested on animals depicting an increased rate of wound contraction and epithelialization.
Treatment of diabetes mellitus by employing artificial pancreas, instead of pancreas transplantation use of beta cells and for oral delivery of insulin use of nanospheres of biodegradable polymer to bypass gastric acids are few applications of nanotechnology in diabetes treatment.
Reconfigurable electronic materials
A materials chemical composition and physical properties can be reversibly reconfigured by controlling the internal ion distribution in a solid state film using an applied electric field at room temperature after the device is fabricated. Nanotechnology enables the reconfiguration of a wide range of materials including dielectric films, and has led to the development of new device concepts such as resistive random access memory. Physical reconfiguration also enables memory and logic operations to be merged in the same device for efficient in-memory computing and neuromorphic computing systems. Coupled electrical, optical and magnetic effects can also be obtained.
Nanotechnology has enabled farmers and agricultural scientists to use nano-fertilizers which consist of nano-sized nutrients, nano-coated fertilizers, engineered metal oxide or carbon based nanomaterials along with nanopesticides which consist of nano-formulation of traditional active ingredients or inorganic nanomaterials for a targeted and controlled release of these agrochemicals which is aimed to obtain their fullest biological efficacy without overdosage.
Micronutrient deficiencies are prevalent in many underdeveloped countries and are a cause of serious socioeconomic problems. Various studies have attempted nanoencapsulation of some of the important nutrients. These encapsulated molecules include proteins, zinc, calcium, iron etc. for better absorption, digestion and cell uptake.
Water purification membranes
Development of more efficient membranes for water purification includes the use of molecular-level design approaches to prepare thin, defect-free and selective layer on microporous supports. It is essential to enhance the fouling resistance of nanoporous membranes which can be done by micrografting fouling-resistant polymers such as zwitterionic polymers and polyethylene oxide (PEO).
Nanomaterials are extensively used in photovoltaics. There has been a significant increase in the efficiency of PV solar cells while the cost of manufacturing and electricity production has reduced at an unprecedented rate. Other than photovoltaics, fuel cells are employing nanomaterials for hydrogen production, storage and transformation into electricity by more efficient catalysis for water splitting and nanostructured materials for higher hydrogen adsorption capacity.
Nanotechnology is being used to develop corrosion free Aluminum to be used for fabrication aircraft body. Aluminum coated with nanocomposite with urethane top coating presents extreme corrosion resistance in salt-soaking tests due to barrier effect of positively charged nanosize porous silica particles and urethane top coating. Similar types of coatings are being used for long lasting and reliable processing of aircraft skin making them last longer resulting in cost-cutting and lifetime enhancement of the aircraft.
These are a few examples from thousands and thousands of applications where nanotechnology has played a significant role. It still is a developing technology and there is much more to be done to completely understand the processes happening at the nanoscale thus allowing us to manipulate those processes for our benefit. Nanotechnology may break the barriers faced by conventional technology and thus provide with sustainable solutions to those problems.