The third decontamination cycle on a single shift. An operator wearing nitrile gloves wipes the control panel of an analyzer with an isopropanol solution. The symbols on the buttons are losing their sharpness. The tactile feedback – that perceptible “click” confirming a press – is becoming less distinct. One uncertain press, the measurement sequence is interrupted, and the sample has to be repeated.

In laboratory equipment, the HMI panel – the interface through which the operator controls the device – is a component that directly contributes to the reliability of the result. An OEM manufacturer, meaning a company that designs a finished device using its own and third-party components, faces a choice: either treat the interface as an integral part of the design from day one, or pay for that decision later through complaints and service issues.

A laboratory is not a production hall

On a production floor, a keyboard has to withstand dust, lubricants, and vibration. In an analytical laboratory, the stresses are different and, contrary to intuition, can sometimes be even more demanding for materials.

A laboratory environment means exposure to aggressive chemicals: acids, alkalis, and organic solvents. It means disinfection performed several times during a single shift, as well as UV-C radiation – ultraviolet light used to sterilize rooms – which can degrade many plastics much faster than years of normal use.

What may appear to be a milder environment can, in practice, impose greater material requirements than typical heavy industry. An operator panel that can work reliably for a decade on an assembly line may lose the readability of its markings within just a few months in a laboratory environment.

Chemical resistance, not aesthetics

An OEM manufacturer selecting an interface for laboratory equipment should begin with the question of what chemicals the panel will come into contact with, and only then consider its appearance. The range of substances found in a typical laboratory is broad: from isopropyl alcohol and ethanol, through acetone and xylene, to hydrochloric acid and sodium hydroxide. Each substance interacts differently with materials – some cause surface clouding, others degrade seals, while others dissolve protective coatings.

Importantly, in laboratory practice, these substances rarely act in isolation. During a single shift, a panel may come into contact with an acid during analysis, a solvent during workstation cleaning, and a chlorine-based disinfectant at the end of the procedure. The material must withstand multiple substances, with each subsequent exposure acting on a surface that may already have been weakened.

A single contact with an aggressive reagent rarely destroys a panel. Thousands of exposure cycles spread over years of operation, however, certainly can. A material that looks promising on paper may lose its properties after a year of intensive disinfection. Symbols fade, protective coatings lose their continuity, seals harden and cease to perform their function.

Readability that does not depend on lighting conditions

An analytical laboratory is an environment with constantly changing lighting conditions. Around a laminar flow cabinet – a device providing a controlled flow of clean air – harsh fluorescent lighting may dominate. Inside a dark analytical chamber, the environment may be dim. At a workstation with a UV lamp, a specific light spectrum can distort color perception.

The operator interface must remain readable under all these conditions. Appropriate contrast between symbols and background, carefully considered typography, and properly designed backlighting are decisions that must be made at the design stage, not after complaints arise.

Operating the equipment while wearing protective gloves presents another challenge. An operator wearing nitrile or latex gloves loses some touch precision. The interface must compensate for this with clear tactile feedback, appropriately sized active areas, and a distinct actuation point. When an operator is unsure whether a button has responded, they press it again – and a duplicate command in measurement equipment can be just as costly as no command at all.

Durability measured in decades

Laboratory equipment is designed for long service. The typical lifecycle of a diagnostic device is seven to ten years. During that time, the HMI panel may have to withstand millions of button actuations, tens of thousands of disinfection cycles, and constant exposure to substances that systematically test the limits of material durability.

Over such a long period, actual durability matters – measured under the customer’s real laboratory conditions. The difference between a material that begins to lose its printed markings after 40,000 cycles and one that remains resistant beyond 100,000 cycles can mean the difference between a panel that fails before the end of the equipment’s service life and one that lasts for its entire lifecycle.

The way graphics are applied is another critical factor. Printing on the outer surface of the front foil may begin to fade after the first months of intensive cleaning because every wipe creates micro-abrasion that gradually removes the ink layer. With reverse or second-surface printing, the graphics are placed on the inner side of the film and protected by the entire thickness of the material. The operator can scrub the panel for years while the symbols remain intact because the cleaning cloth never comes into direct contact with them.

The type of protective coating, switching technology, thickness and grade of the front foil – each of these elements affects whether the interface will operate in the fifth year as reliably as it did on the day of acceptance.

Replacing a panel in laboratory equipment is not simply the cost of a component. It can mean equipment downtime, recalibration, and, in many cases, repetition of qualification procedures. An OEM manufacturer that saves a dozen percent on a material at the design stage may end up paying many times that difference over the lifetime of the device.

Equipment qualification starts with the interface

In regulated environments such as pharmaceuticals, medical diagnostics, or accredited laboratories, equipment undergoes formal qualification procedures before being approved for operation. This process typically includes three stages:

• verification that the equipment has been installed correctly,
• testing of its operation across the full operating range,
• confirmation of stability under actual operating conditions.

As the point of contact between the operator and the device, the HMI panel requires particular attention. The materials used must have documentation confirming their suitability for the requirements of the specific environment. The construction must support cleaning without compromising sealing. The entire solution must be designed so that it does not delay certification of the finished product.

An OEM manufacturer that selects an interface without considering the qualification pathway may discover the problem only during an audit – when changing the supplier means repeating the entire testing cycle.

How does Qwerty approach it?

At Qwerty, designing an interface for laboratory equipment begins with an analysis of the environment in which the device will operate. Before the first graphic layout is created, we establish the operating conditions:

• which chemicals the panel will regularly come into contact with,
• how frequently and by which methods it will be disinfected,
• under what lighting conditions the operator will use it,
• whether the device requires documentation supporting qualification processes,
• what the expected product lifecycle is.

Based on this information, we select materials, printing technology, and switch types according to the requirements of the specific project.

From our perspective, an interface for laboratory equipment requires the same design discipline as a measurement circuit or optical system. The difference is that an interface failure is noticed first by the operator – rather than only by the service department.

Process integrity is decided on the surface of the panel

The third decontamination cycle, the fifth, the hundredth. The symbols are either readable or they are not. A button either confirms the press or leaves the operator uncertain. A seal either protects the electronics or allows a solution to penetrate and gradually damage the conductive traces underneath.

In laboratory equipment, the operator interface either supports process integrity or undermines it.

That is precisely why the decision about its construction should be made at the very beginning of the project.