Seeing our cities in a new light
Interromate’s robust optical fibre sensors provide the right ‘eyes’ to monitor the health of urban infrastructure threatened by harsh environments.
Urban life in Australia is a focus of public discussion, especially around sustainability and population distribution. With 67% of Australians living in capital cities, these areas often feel ‘full’ but continue to expand rapidly. Meanwhile, booming regional areas face mounting pressure on housing, services and infrastructure.
Skyrocketing urbanisation highlights the need for smart cities that use sensors, the internet and automation to enhance the quality of life across the country.
Sensor data helps manage a city’s assets, resources and services efficiently, ultimately improving operations. Currently, electric sensors are common but have a short lifespan in hostile spaces such as the corrosive environment in wastewater treatment pipelines. Their reliance on electricity also prevents them being used in environments with explosion, fire or radiation risks.
Light-based sensing offers a solution. Interromate, a commercial venture based at Macquarie University and a pioneer in advanced laser microfabrication, has developed photonic sensors that are uniquely capable of operating in harsh environments.
Their fibre optic sensors provide long-term, real-time data that traditional sensors cannot match. They use Bragg gratings, which act like a light filter, reflecting specific wavelengths of light while transmitting all others.
Bragg gratings are created using ultrafast laser inscription that focuses a laser beam to permanently modify the internal structure of the glass at the heart of the fibre optic. These modifications only need to be made in a couple of millimetres of the fibre to have the desired effect.
By filtering the light, Bragg gratings act as colour-specific mirrors inside the fibre. Interromate’s system tracks the light reflected from these mirrors, providing information about conditions at specific locations along the fibre. Environmental factors affect the Bragg gratings, changing the frequency of the reflected light. For example, heating a glass fibre causes expansion, while cooling causes contraction, altering the light reflected by the sensor. Multiple Bragg gratings can be placed at different locations within the fibre to monitor various environmental changes, such as temperature, corrosion, humidity and strain.
Interromate has removed one of the biggest challenges dooming electric sensors by minimising the impact of environmental conditions on the sensor components, significantly improving sensor readout accuracy and longevity. This is made possible by the inert nature of the sensors. Designed for use in a variety of hostile environments, including explosive, corrosive, high-voltage or hazardous areas, these fibre optic sensors can operate for several years, outperforming electronic analogues that fail after just a few days.
And it is not just the fibre that is on offer. Interromate pairs a commercially available optical fibre with either a custom-designed, user-friendly hardware package or an off-the-shelf interface, depending on the scale needed.
This technology is already making its presence felt. In the water utility sector, Interromate is partnering with Sydney Water and Melbourne Water to help them better manage and rehabilitate wastewater infrastructure.
Corrosion in deteriorated concrete gravity sewers can lead to premature pipe failure. Photonic sensing promises to improve sewer pipe management by providing in-situ monitoring capabilities, reducing the need to enter sewer pipes, and offering superior predictive corrosion strategies. This approach mitigates health risks to the public and leads to significant cost savings, allowing compromised pipes to be rehabilitated before corrosion goes too far.
Infrastructure sensors are the hidden foundation of smart green cities. They are essential for detecting developing problems, predicting when infrastructure components will reach the end of their life and extending the service life of city assets.
Interromate is at the forefront of smart city technology that will contribute to the sustainability and management of Australia’s expanding urban environments.
For more information on Interromate, visit https://interromate.com. For more information on their partners, visit https://www.sydneywater.com.au and https://www.melbournewater.com.au/
Published 15 October 2024 in ANFF’s 2024 Casebook ‘ANFF NEXT‘
Posted 06 February 2025
