Different from the inorganic counterparts like silicon, organic semiconductors can operate under bending or stretching. Usually a thinner film can have stronger capability to bend. Other than bending, a thinner or smaller device can also offer a faster response time which is particular important for sensor application if immediate information is needed. These ultra-flexible sensors are very popular research areas and their applications cover electronic, smart sensing and etc.
Recently, a University of Hong Kong (HKU) research team led by Dr Paddy Chan Kwok-leung of the Mechanical Engineering Department, in collaboration with Professor Gilberto Leung Ka-kit (Tsang Wing-Hing Professor in Clinical Neuroscience) and Dr Anderson Tsang Chun-on of Surgery, and Professor Xu Aimin of Department of Pharmacology and Pharmacy, have developed a C-reactive protein (CRP) sensor integrated onto a medical catheter for direct CRP sensing. This organic sensor has a total thickness less than one micrometer (~1/50 of Asian human hair), which can significantly save the time for sample and data collection, from currently a few hours to 10 minutes or less. In other words, testing and curing of inflammation can be speeded up by 30 times. The real-time signal read out has a great potential in allowing the doctors to take necessary immediate actions.
This mechanically flexible organic electronic device developed by Dr Chan’s team, as a demonstration of concept, is to measure the biological information in real-time. This device can sense the CRP level down to 1ug/mL, and hence more sufficient to deviate the health condition of the patients. The research finding was published recently in journal Advanced Science.
The CRP sensor developed by the HKU research team is just one example to demonstrate the concept of the ultrathin devices. Other sensors such as neurotransmitter, and bacteria sensors can also be used. Other than the high sensitivity and fast response time, another major achievement of this ultra-thin and ultra-flexible sensor device is their compatibility with the standard sterilization processes adapted in the hospitals. Dr. Chan’s team has developed a “capsule-like” CTYOP encapsulation layer which allows the device to withstand high pressure, temperature and moisture environment. By using a CYTOP capsule with only 250 nm, this device can withstand boiling water or hot steam for more than 30 minutes without showing performance degradation. This sterilization compatibility makes the device an appropriate tool to be used together with surgical instruments in operation room which requires aseptic environment.
In the future, Dr. Chan and his team will further enhance the sensing power of the devices by integrating neurotransmitter and pressure sensors onto the catheter. The team will also develop a sensor platform for the clinical tests on animals. Other than the CRP sensor for the blood, the team also plans to measure other bio-markers especially the neurotransmitters or other information from the cerebrospinal fluid which can provide valuable real time information of the patients suffering from head injury or strokes.