Hygienic design for touchscreen kiosks
Author : Ian Crosby | Sales & Marketing Director | Zytronic
01 August 2021

Zytronic_Hygenic design_easy cleaning
Closely regulated practices for contamination avoidance have been in place for decades in the food & medical sectors. For shared equipment such as control panels or medical instruments, using hygienic design principles to ensure that the interface doesn't become a haven for bacteria or other microbes is vital to prevent cross-contamination.
This article was originally featured in the August 2021 issue of EPDT magazine [read the digital issue]. And sign up to receive your own copy each month.
But as Ian Crosby, Sales & Marketing Director at display & touch solutions expert, Zytronic explains, with touchscreen technology increasingly becoming an integral part of our daily lives, from ordering at a fast food restaurant to buying a ticket at a train station or cinema, or using an interactive map in a shopping centre or exhibit in a museum, hygienic design, combined with suitable cleaning regimes, is fast becoming essential – especially considering the recent pandemic…
When designed with the right touch technology, such as projected capacitive (PCAP) touch, interfaces can be completely flush with kiosk housings, making them easy to effectively clean. With such hygienic design principles, operatives can quickly disinfect units following a regular cleaning regime. Some kiosks now dispense sanitising wipes or gels for customers to use before and after touching the surface. Older bezel frame designs or mechanical controls, on the other hand, are difficult to clean because of hard to reach nooks and crannies, which can harbour pathogens.
One story that gained widespread media coverage a couple of years ago was a newspaper report that touchscreens used on some self-service kiosks in fast food restaurants tested positive for coliforms, more commonly known as faecal bacteria. This is a worry for those customers who order, collect and eat food without washing their hands or sanitising with gel.

Zytronic_Hygenic design_Coca Cola
If you buy soft drinks from fast food restaurants, you may have used the Coca Cola Freestyle® Self-Serve 9000 beverage dispenser, which enables customers to select their preferred sparkling or still beverage, or design their own flavours. These machines epitomise ‘hygienic by design’ principles. A transparent polycarbonate moulding mounts on top of the touchscreen, creating a design without an aperture for the touchscreen, making it both stylish and easy to wipe clean. However, even through the overlying plastic front, by adjusting the settings in the touch sensor driver, the ZyBrid sensor can detect touch events reliably and accurately.
Other touch settings on the driver are also possible on the in-house designed and developed single and multiple touch controllers. For example, with a few simple adjustments, the ZyBrid sensor can not only respond to the touch of a bare finger, but also to gloved hands or a conductive stylus. This capability enables users to wear latex gloves in food processing or medical sectors, thus avoiding direct skin contact with potentially contaminated screens.
Another example of stylish and hygienic self-service kiosk design can be seen with Qmatic’s Intro 17™ solution. The all-in-one unit delivers check-in and queue management via its bespoke, bezel-free Zytronic touchscreen interface. The PCAP touch sensor features a fully flat, all-glass surface, meaning dirt and surface contaminants can be easily cleaned off regularly, making the kiosk ideal for use in busy public environments, such as waiting areas in retail collection points, hospitals and clinics.
Going further, it’s also possible to specify customised touch sensors made using antimicrobial glass or with an antimicrobial coating. The benefit of using either of these approaches is that they help slow down bacterial growth and, given enough time, ultimately kill it. However, it’s essential to point out that, generally speaking, neither of these approaches have a known positive effect killing viruses, such as COVID-19 (and, even if they did, the effect is gradual, not instantaneous).

Zytronic_hygenic design_Qmatic
Realising this obstacle, especially for touch sensors used in public spaces, such as kiosks, vending machines and wayfinders, Zytronic developed a contactless sensing option. Called ZyBrid hover, operation of this sensing technology can be switched between direct touch or contactless mode as required. In direct touch mode, the glass sensor overlay can be quickly and hygienically cleaned. In ‘hover’ mode, user interactions can be detected 30mm or more away from the surface of the glass.
Although there are alternative PCAP-based technologies available on the market, they typically only support a maximum distance of 10mm for the glass surface and, generally, can’t detect a touch from a gloved hand. This is because they rely on either ITO (indium tin oxide) or a metal mesh to create the projected capacitive matrix on the rear of the sensor, both of which have relatively low conductivity. In contrast, for ZyBrid hover, Zytronic deposits a proprietary copper matrix pattern on the rear of its touch sensors. When used in combination with its ZXY500™ controller and custom firmware, changes in the transferred energy are detected further than ever before.
One potential application for ZyBrid hover is for lift control panels. Typically, these areas are high usage, multi-user, public touchpoints. Traditional panels generally rely upon mechanical buttons that are difficult to clean and harbour microbes, creating a risk and concern for users. By combining a display overlaid with a completely flat, easy to clean glass ZyBrid hover touch sensor, this hygiene problem is solved, and, when operating in ‘hover’ touch mode, there is no need to come into physical contact with the control surface.
Aside from PCAP-based technologies, most other techniques used to enable a touchscreen to detect an interaction without physical touch rely upon infrared or camera-based touch detection hardware mounted around the front edges of the screen. Such arrangements inevitably create unsightly, protruding bezels, which can harbour pathogens and make the screen difficult to clean effectively. They are also susceptible to “false” or accidental touches, as they will react to any object breaking the IR light beams or coming into view of the camera – such as a sleeve, drop of rain or a falling leaf. Furthermore, intense direct sunlight and dust/debris accumulating on the surface can impede performance or prevent it from working.

Zytronic ZyBrid hover Elevator Touch Control
If a combination of fixed function keys and a dynamic/changeable touchscreen area is desirable for an application, say for a control panel in a food processing plant, then Zytronic’s ZyBrid VK capability enables the creation of a single, completely flat and hygienic user interface. This avoids the need for mechanical keys or buttons, which can potentially harbour microbes. The resulting “hybrid” touch sensor is also managed by one ZXY500 multi-touch controller, making design and integration simple and cost effective.
Furthermore, where a higher degree of tactility is needed, so users can ‘feel’ their way across a flat touchscreen, Zytronic can machine dimples, grooves and dials into the front of the glass sensor. As with the ZyBrid VK solution, the entire user interface remains uninterrupted by holes and bezels and is, therefore, straightforward to clean, with few places where microbes can lurk.
Contrary to some perceptions, self-service kiosks can play a critical role in reducing the risk of microbial infection, as they minimise face-to-face contact and help maintain social distancing. Zytronic cannot stress enough the importance of combining hygenic touchscreen design together with rigorous and regular disinfection.
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