A wafer-thin patch that, when applied to any part of the human body, is able to monitor oxygen levels and take action to ensure the body stays healthy and can properly carry out its functions. But how does it work? Once on the skin, or applied to the surface of an internal organ after a small operation, the patches make contact with the capillaries below the surface and measure how much oxygen they contain. The idea was dreamt up by a team of researchers at University of California, Berkeley, as a way of identifying lesions or injuries that would otherwise go unobserved, before healing them in real time.
The system would be especially useful in the post-op stage or after transplants, when it’s vitally important that the area of the body affected is kept under surveillance. It’s the latest development in the world of flexible electronics, a futuristic branch of science focusing on the creation of devices that can adapt to the internal shapes and surfaces of the human body. It’s the next generation of wearable, biocompatible devices, in miniature form.
Flexible electronics under the microscope
These devices are generally designed to be so thin that they are barely visible, so that they are as non-invasive as possible for the habitat in which they are applied. You could compare them to the temporary tattoos popular with children – except they’re even thinner!
However, thanks to advancements in electronic miniaturisation, these almost 2D devices can contain huge quantities – and varieties – of sensors. They act like « noses », capable of sniffing out substances and conditions in biological tissue, including the concentration of oxygen, sugars, protein and harmful molecules, and detect signs such as increased temperature or blood pressure.
Interactive patches
Once the specific information required has been collated, the device still needs to transmit to the patient, or the healthcare worker involved. Therefore, as well as being able to feel, it’s also vital that these devices are able to communicate. It’s a bit like the red light coming on to tell us that we need to fill up our cars with petrol.
The scientists are trying all options when it comes to this area, with ideas including microscopic Wi-Fi systems capable of transmitting data directly to a doctor’s computer or the patient’s smartphone via an app, and systems integrated in the body, such as light signals. Yet the most innovative – and probably the most fascinating – idea is for a wearable electrocardiogram prototype, which would be worn on the wrist and can inform us in real time if our heart is in good or bad shape. How? It records the vital signs of the heart, with a particular focus on the rhythm (just like a doctor does when he places his stethoscope on our skin), keeping us up to date through an ultra-thin OLED display affixed to our skin. More specifically, a heart-shape logo will light up in red when everything is fine, with the heart turning blue to notify us that we need to contact a doctor.
Not just diagnostics
As with all diagnoses, the next step is treatment. In this field, the world of flexible electronics is setting itself some truly revolutionary objectives. One of the most ambitious – but one that seems within reach for the medical world – is to create a sort of « electronic skin » that serves as an artificial fingertip to restore the sense of touch to people that have lost theirs as a result of an accident or disorder affecting the nervous system. But that’s not all. Thanks to the combination of increasingly soft devices and functional materials, some of which are nanoscopic, measuring just billionths of a metre, work is underway to develop systems for use in the optical field. This would involve the device being inserted into the eyeball. Once established and integrated with the neural circuitry, the device would be able to work like a retina, restoring the transmission of visual stimuli and giving – or returning – the sense of sight.23