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Success Story: AFRL Confined Space Monitoring Armband


Every year, workers are injured and killed due to the build up carbon monoxide/dioxide and the high prevalence of volatile organic compounds while working in confined spaces. These problems are further compounded by the narrow entry and exit points from these spaces.

Current methods of monitoring worker health and safety in confined spaces rely on bulky atmospheric monitors and continuous visual observation. These methods are labor intensive and inaccurate, as they cannot monitor the atmosphere directly around the workers or indicate when workers are in a dangerous situation.

This problem has long been recognized by aircraft maintenance teams working on fuel tanks at Warner-Robbins Air Force Base. The team came to NextFlex for assistance in developing a wearable device to monitor the atmospheric levels surrounding workers in confined spaces.

NextFlex’s Role

With funding from the Air Force Research Laboratory (AFRL) and support from the maintenance team at Warner-Robbins Air Force Base, NextFlex developed a next generation Flexible Hybrid Electronics (FHE) confined space monitoring device. The device is designed as a flexible conformal armband capable of monitoring volatile organic compound concentrations, oxygen levels, temperature and humidity. Processing and communication are provided by a Bluetooth radio that can connect to a cell phone and allows for remote monitoring of the worker from a central control station. The design is powered by an onboard battery which can be wirelessly recharged using an embedded Qi charging circuit and brings together an incredibly dense array of features into a highly flexible, wearable and robust additively manufactured electronics format.

In addition to the high complexity of the design, significant effort has been placed into optimizing the antennas to maximize wireless range. Furthermore, the design was created to be highly secure, meeting FIPS 140-2 requirements, as well as meeting intrinsic safety requirements for explosion proofing in gaseous atmospheres.

“NextFlex has been highly innovative and responsive in working to advance the state-of-the-art in FHE in support of Air Force confined space maintenance requirements for an intrinsically safe, truly wearable atmospheric sensing capability which has been lacking to date. This AFRL-funded project builds on prior FHE advancements at NextFlex which enabled a flexible ‘Arduino®-like’ microcontroller and applies it to a real-world Air Force problem. They’ve refined this FHE microcontroller to operate CMOS gas sensors and added necessary power and comms to enable wearable chemical sensing in hazardous maintenance environments and replace handheld systems,” said Mathew Dalton, Research Chemist and Program Manager with Air Force Research Laboratory, Materials and Manufacturing Directorate. “Ultimately this will help keep maintainers safe while reducing costs and improving productivity!”


When deployed, the FHE confined space monitoring armband designed by NextFlex will directly integrate into a framework already being deployed for the Air Force by Aptima Technologies. The armband will provide accurate and continuous monitoring of workers in highly confined spaces remotely. This new technology will reduce the number of personnel required to perform routine maintenance tasks, while simultaneously increasing the safety of the workers through monitoring of their working environment. By enabling unique monitoring wearables, FHE is helping NextFlex’s partners in the Air Force make the job safer for its personnel.

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