, researchers from the University of Surrey, in collaboration with the University of Bath, detail how they have built on their ground-breaking research by developing extraction fibres to draw lithium from under the skin.
They combined lithium extraction with a lithium sensor fibre and reference fibre to create a miniaturised and flexible potentiometric cell - a wearable monitor that can be used by patients without the need to be "primed" in solution.
The researchers demonstrated that their monitor was able to detect lithium and, through their lab tests, they found that their device could also determine the lithium concentration levels and potentially give a warning signal that high levels had been reached.
The team is now looking to understand and investigate whether it is possible for these devices to be sensitive enough to detect extremely narrow therapeutic ranges of lithium.
Many physical wearable sensors have been developed to monitor people's temperature, heart rate and respiration rate and, while wearable glucose monitors are currently on the market, there are few other commercial wearable chemical sensors that exist.
It is believed that using wearable chemical sensors at home, instead of a traditional clinical setting, for screening or follow up care would help to reduce the burden on health professional's time.
Dr Carol Crean, Senior Lecturer in Physical and Material Chemistry at the University of Surrey, said: "We are incredibly excited by the potential of this proof-of-concept study, which has shown that wearable fibre-based lithium sensors are viable and potentially life changing for the many living with bipolar disorder.
Importantly, these devices could also save valuable time for health professionals because most of the monitoring of the therapeutic drug can be done at the patient's convenience."