Instruct: Given a question, retrieve relevant passages that can help answer the question.
Query: When was the first synthetic self-cleaning surface released?
Synthetic setae emulate the setae found on the toes of a gecko and scientific research in this area is driven towards the development of dry adhesives. Geckos have no difficulty mastering vertical walls and are apparently capable of adhering themselves to just about any surface. The 5-toed feet of a gecko are covered with elastic hairs called setae and the ends of these hairs are split into nanoscale structures called spatulae (because of their resemblance to actual spatulas). The sheer abundance and proximity to the surface of these spatulae make it sufficient for van der Waals forces alone to provide the required adhesive strength.[2] Following the discovery of the gecko’s adhesion mechanism in 2002, which is based on van der Waals forces, biomimetic adhesives have become the topic of a major research effort. These developments are poised to yield families of novel adhesive materials with superior properties which are likely to find uses in industries ranging from defense and nanotechnology to healthcare and sport.
The Paradise Cleanseat Power by CWS can be installed on standard toilets with access to power supply and water connection. The cleaning process is executed repeatedly after each use by a sensor or automatically (triggered by flush). The hygiene lock extends out and positions itself on the seat, sprays fresh tap water and the CWS cleaning liquid onto the surface of the toilet seat, which then completely rotates around its axis one time. The wiper made of a highly flexible specialised synthetic material removes any dirt, germs, water and cleaning liquid from the seat surface without leaving any residue. The cleaning process takes approx. 15 seconds, than the hygiene lock retracts to its initial position. It was first introduced in 1993 is manufactured in Switzerland.
One of the most commonly used self-cleaning products, titanium dioxide, utilizes a unique self-cleaning mechanism that combines an initial photocatalytic step and subsequent superhydrophilicity. A titanium dioxide coating, typically on glass windows, when exposed to UV light, will generate free electrons that will interact with oxygen and water in the air to create free radicals. These free radicals will in turn breakdown any fouling organic matter deposited on the surface of the glass. Titanium dioxide also changes the normally hydrophobic glass to a superhydrophilic surface. Thus, when rainfall occurs, instead of water beading up on the window surface and instantly falling down the glass, rain drops will rapidly spread out on the hydrophilic surface. The water will then move down the surface of the window, as a film rather than a droplet, essentially acting like a squeegee to remove surface debris.
Shark skin is another example of antifouling, self-cleaning and low adhesion surfaces. This hydrophilic surface allows sharks to maneuvers fast in water. Shark skin is composed of periodically arranged diamond-shape dermal denticles, superimposed with triangular riblets.[26]
Gecko feet are hydrophobic, but that is not the only property that assists in their self-cleaning nature. Estrada and Lin created polyproppylene, polyethylene, and polycaprolactone nanofibers using a porous template.[49] These nanofiber geometries were shown to be self-cleaning in fiber dimensions of 5, 0.6, and 0.2 microns.[49] However, a hydrophopbic surface alone does not explain the perpetually clean toe pad of the gecko, even in dry environments, where water is not available for self-cleaning. This resulting fouling is a common problem for reversible adhesives modeled after the gecko toe pad. Digital hyperextension, or a movement of the toe with each gecko step, contributes to the self-cleaning.[50] A surface or system that mimics this dynamic self-cleaning process has yet to be developed.
Biomimicry is the imitation, or mimicry, of biological systems, models, or structures, in synthetic areas. Oftentimes, biological materials can produce structures, that have properties and qualities far exceeding what synthetic materials can achieve. Biomimicry is being used to create comparable properties in synthetic materials, particularly in wettability and self-cleaning abilities of self-cleaning surfaces.
The first instance of a self-cleaning surface was created in 1995.[1] Paz et al. created a transparent titanium dioxide (TiO2) film that was used to coat glass and provide the ability for the glass to self-clean. The first commercial application of this self-cleaning surface, Pilkington Activ, was developed by Pilkington glass in 2001. This product implements a two-stage cleaning process. The first stage consists of photocatalysis of any fouling matter on the glass. This stage is followed by the glass becoming superhydrophilic and allowing water to wash away the catalyzed debris on the surface of the glass. Since the creation of self-cleaning glass, titanium dioxide has also been used to create self-cleaning nanoparticles that can be incorporated into other material surfaces to allow them to self-clean.[2]
Synthetic surfaces allow racing to take place in bad weather conditions, when it may otherwise be cancelled, and for this reason are sometimes referred to as All Weather surfaces. Manufacturers of synthetic racetrack surface materials promote the fact that synthetic tracks have drainage attributes that are better than natural surfaces. 
Glass silica beads in an epoxy resin,[41] and the electrochemical deposition of gold into dendritic structures[40] has also created synthetic biomimetic surfaces similar to lotus leaves.
There are several biological surfaces that have superhydrophobic properties far superior to any synthetic materials: lotus leaves, rice leaves, cicadia wings, and butterfly wings.
When a water droplet is on a surface that is not flat and the surface topographical features lead to a surface area that is larger than that of a perfectly flat version of the same surface, the Wenzel model is a more accurate predictor of the wettability of this surface. Wenzel's model is described by the following equation:
To fabricate synthetic self-cleaning surfaces, there are a variety of methods[8] used to obtain the desired nanotopography and then characterize surface nanostructure and wettability.
The phenomenon of ultrahydrophobicity was first studied by Dettre and Johnson in 1964 using rough hydrophobic surfaces. Their work developed a theoretical model based on experiments with glass beads coated with paraffin or PTFE telomer. The self-cleaning property of ultrahydrophobic micro-nanostructured surfaces was studied by Wilhelm Barthlott and Ehler in 1977, who described such self-cleaning and ultrahydrophobic properties for the first time as the "lotus effect"; perfluoroalkyl and perfluoropolyether ultrahydrophobic materials were developed by Brown in 1986 for handling chemical and biological fluids. Other biotechnical applications have emerged since the 1990s.
The ability of a surface to self-clean commonly depends on the hydrophobicity or hydrophilicity of the surface. Whether cleaning aqueous or organic matter from a surface, water plays an important role in the self-cleaning process. Specifically, the contact angle of water on the surface is an important characteristic that helps determine the ability of a surface to self-clean. This angle is affected by the roughness of the surface and the following models have been developed to describe the "stickiness" or wettability of a self-cleaning surface.
Superhydrophilicity allows for surfaces to clean away a wide variety of dirt or debris. This mechanism is very different than the aforementioned superhydrophobic surfaces. For superhydrophilic self-cleaning surfaces, cleaning occurs because water on the surface is able to spread out to a great degree (extremely low water contact angle) to get between any fouling debris and the surface to wash away the debris.
It's important to know that this property of self-cleaning appears intrinsic to the setal nano-structure and therefore should be replicable in synthetic adhesive materials. In fact, Kellar Autumn's group observed how self-cleaning still occurred in arrays of setae when isolated from the geckos used.
A recent (2001 Pilkington Glass) innovation is so-called self-cleaning glass, aimed at building, automotive and other technical applications. A nanometre-scale coating of titanium dioxide on the outer surface of glass introduces two mechanisms which lead to the self-cleaning property. The first is a photo-catalytic effect, in which ultra-violet rays catalyse the breakdown of organic compounds on the window surface; the second is a hydrophilic effect in which water is attracted to the surface of the glass, forming a thin sheet which washes away the broken-down organic compounds.
A self-cleaning floor is a floor surface that reduces the amount of chemicals, energy, and human resources associated with cleaning floor surfaces. Such floors are meant for use in hospitals, toilets and other places in which cleanliness is of vital importance. In Europe, most of the leading ceramic tiles and sanitary ware manufacturers have products on the market with self cleaning features.
Self-cleaning surfaces are a class of materials with the inherent ability to remove any debris or bacteria from their surfaces in a variety of ways. The self-cleaning functionality of these surfaces are commonly inspired by natural phenomena observed in lotus leaves, gecko feet, and water striders to name a few. The majority of self-cleaning surfaces can be placed into three categories: 1) Superhydrophobic, 2) Superhydrophilic, and 3) Photocatalytic.
The household chore of doing the laundry began to change with the introduction of washing powders in the 1880s. These new laundry products were pulverized soap. New cleaning-product marketing successes, such as the 1890s introduction of the N. K. Fairbank Company's "Gold Dust Washing Powder" (which used a breakthrough hydrogenation process in its formulation), and Hudson's heavily advertised product, Rinso, proved that there was a ready market for better cleaning agents. Henkel & Cie's "self-activating" (or self bleaching) cleaner, Persil; (introduced in 1907); the early synthetic detergent, BASF's Fewa (introduced in 1932); and Procter & Gamble's 1933 totally synthetic creation, Dreft (marketed for use on infant-wear) —all indicated significant advances in the laundry cleaning product market.
Unlike conventional adhesives, gecko adhesive becomes cleaner with repeated use, and thus stays quite clean around everyday contaminants such as sand, dust, leaf litter and pollen. In addition, unlike some plants and insects that have the ability of self-cleaning by droplets, geckos are not known to groom their feet in order to retain their adhesive properties – all they need is only a few steps to recover their ability to cling to vertical surfaces.
Taklon brushes are more hygienic than real hair brushes. Natural hair has an irregular surface which traps powders, dead skin cells, bacteria and chemicals. Cleaning may not necessarily remove these particles. Because of this, regular cleaning with disinfectants is required to prevent skin irritation. Taklon lacks these surface irregularities, making it easier to clean properly. This decreases irritation. Because Taklon is synthetic, animal cruelty is not an issue.
The hanging mercury drop electrode (HMDE) produces a partial mercury drop of controlled geometry and surface area at the end of a capillary in contrast to the dropping mercury electrode (DME) which steadily releases drops of mercury during an experiment. The disadvantages a DME experiences due to a constantly changing surface are not experienced by the HMDE since it has static surface area during an experiment. The static surface of the HMDE means it is more likely to suffer from the surface adsorption phenomenon than a DME. Unlike solid electrodes which need to be cleaned and polished between most experiments, the self-renewing HMDE can simply release the contaminated drop and grow a clean drop between each experiment.
In 1982, High Density Plastics launched the first full-size synthetic skating floor under the trade name of Hi Den Ice. The surface was made of interlocking panels of high-density polyethylene which became an ice rink when sprayed with a gliding fluid. The surface needed to be cleaned off and resprayed once a month. In a dry form, the panels were also usable for other indoor sports.
Control over surface wettability is a critical aspect of self-cleaning surfaces. Both superhydrophobic and superhydrophilic surfaces have been used as self-cleaning materials.