Figure 1: Illustration of the different self-healing approaches for organic semiconudctors.

According to the Office for National Statistics, healthcare expenditure in the UK amounted to £258 billion or 12% of gross domestic product in 2020, compared to £123 billion (7.4% of GDP) in 2000. The pressure on future healthcare costs is further amplified, by rapidly ageing societies, a problem particularly pronounced in many Western economies and China. According to the 2021 census, 18.6% of the total UK population (11 million people) were aged 65 or older. Preventive healthcare is often much more cost efficient, yet relies on regular pre-emptive diagnostic testing, which in itself is time consuming and work intensive. To enable more cost effective preventive healthcare and timelier medical treatment, it is necessary to develop cheap and user friendly sensors for enhanced remote patient monitoring. Being able to continuously monitor health conditions would dramatically improve pre-emptive diagnostics, as well as early disease detection and treatment.

In contrast to crystalline silicon-based semiconductors, flexible organic semiconductors allow the fabrication of electronic devices on conformal substrates, making them ideal material candidates to integrate into skin-wearable electronic sensors. Skin-integrated electronics are non-evasive, allow direct contact with the skin for analyte uptake and significantly improve patient well-being due to enhanced comfort and wearability. However, one of the common features all soft materials share, including organic semiconductors, is their susceptibility to environmental stresses, such as mechanical damage, chemical attack, temperature fluctuations and radiation damage. These constant stresses lead to the formation of cracks in the structure, resulting in the loss of the material’s physical properties. While organic semiconductors can be bendable if processed appropriately, they struggle to withstand elongation, commonly resulting in the breakdown of the mechanical and electrical properties, when deformed beyond the yield point. Our research group is interested in developing more robust organic semiconductors, that do not only tolerate extreme deformations, but “self-heal”. Self-repairing organic semiconductors are able to autonomously cure inflicted structural damage and restore the original electrical and mechanical properties of the semiconductor. The development of self-healing, robust organic semiconductors, will allow us to pursue their integration into fully skin-wearable biosensors for non-invasive metabolite monitoring associated with diabetes (glucose), fatigue (lactate) and stress (cortisol).

Recent publications

Composites Communications 2021, 28, 100952. Link

Nat. Commun. 2020, 11, 3362. Link

Adv. Funct. Mater. 2020, 30, 2000663. Link