Rigorous cleanroom certification requires accurate, real-time data. Microchip technology provided by sophisticated integrated circuits ensure sensors are up to the task, says Ross Turnbull.
Cleanrooms, as defined by ISO 14644- 1:2015, are controlled environments where airborne particles are tightly regulated.
These spaces are fundamental in various manufacturing and research processes. For example, in pharmaceutical laboratories, cleanrooms help ensure that medicines, vaccines. and medical devices remain uncontaminated by allergens, microbes or other hazardous particles. Similarly, in the energy sector – particularly in battery development, fuel cell innovation and materials research laboratories – cleanroom environments help protect sensitive components and ensure data integrity by minimising contamination and electrostatic interference.
ISO certifications for cleanrooms range from Class 1 – the most stringent – to Class 9, depending on the product’s vulnerability to particulate matter. However, regardless of class, maintaining conditions requires constant, high-precision environmental monitoring. Even minor fluctuations in temperature, humidity or pressure can impact product quality, slowdown operations or result in the cleanroom being shut down altogether.
So, with such high stakes, how can manufacturers ensure cleanroom compliance is continuously upheld?
Controlling conditions
One of the most vital parameters to monitor is pressure. This is because pressure helps to form a protective barrier, ensuring airborne particles don’t infiltrate or escape the cleanroom.
A common method of achieving this is through differential pressure sensors or transducers, which maintain pressure gradients to prevent contamination. These sensors typically use capacitive or piezoresistive sensing elements to measure pressure differences between the cleanroom and its surrounding areas. This data is then converted into an electrical signal for real-time monitoring and control system feedback.
Beyond particle control, tight regulation of temperature and humidity is also essential. If cleanroom temperatures exceed safe thresholds, shedding of skin cells by workers may surpass what protective garments can contain. IC (integrated circuit)-based temperature sensors are well suited to help tackle this issue as they can quickly respond to temperature changes, due to their ability to produce electrical output proportional to absolute temperature.
Alongside temperature, humidity must also be precisely managed. In electronics cleanrooms, high humidity can lead to condensation on delicate components, while low humidity increases the risk of electrostatic discharge, a common cause of circuit failure and long-term reliability issues. To tackle this challenge, digital humidity sensors are gaining favour due to their compact design and high integration, eliminating the need for separate signal conditioning or conversion components.
ASIC advantage
Although sensor hardware continues to advance with digital integration, the performance of any sensor still hinges on the IC at its core. Unlike general-purpose chips, application specific integrated circuits (ASICs) are tailored specifically for the end application, resulting in significant performance benefits.
Cleanroom environments help protect sensitive components and ensure data integrity by minimising contamination and electrostatic interference
ASICs allow manufacturers to integrate signal conditioning, calibration and processing into one compact chip, maximising measurement precision and improving system response.
For temperature sensing, ASICs help to reduce thermal and electrical noise, simplify multi-point calibration and enable rapid signal processing. This is essential for quickly detecting deviations that could compromise sample sterility or product stability. Pressure sensors also benefit from on-chip amplification, offset compensation and linearisation, ensuring precise control of differential pressure, which is critical for maintaining positive or negative airflow barriers between laboratory zones.
Meanwhile, humidity sensors gain enhanced signal stability and resistance to electromagnetic interference, delivering reliable data even under dynamic airflow conditions. This level of integration helps maintain consistent environmental quality and improves the overall responsiveness of cleanroom control systems.
Standard ICs may eventually be phased out, posing obsolescence risks. On the other hand, ASICs offer extended product lifecycle support, giving sensor manufacturers greater design control and helping them avoid unexpected supply disruptions.
By leveraging ASIC-driven sensors, manufacturers not only meet certification standards but also enhance operational efficiency and safeguard product integrity.
Ross Turnbull is director of business development and product engineering at application specific integrated circuit (ASIC) firm Swindon Silicon Systems
