Multifunctional, Motion Artifact-Free Sensing and Point-of-Care Treatment With Drawn-on-Skin Electronics

Human skin offers a wealth of physiological and physical information that can be utilized to monitor, prevent, and treat adverse health conditions. By directly interfacing electronic devices with the skin, information such as the condition of the heart, the strength of the muscles, the impedance, and hydration of the skin, can all be extracted. Recent advances in soft wearable electronics which attach directly to the epidermal surface have suggested certain pathways. Typically, wearable bioelectronics are structured in the form of patches that are soft, flexible, and/or stretchable and thus, are beneficial to form contact with the curvilinear surfaces of the skin. However, wearable bioelectronics generally suffer from motion artifacts thus leading to misinterpretation and misdiagnoses. This is mainly attributed to the weak adhesion or imperfect conformability, and thus the inconsistent interface between the electronics and skin. Specifically, one of the main sources of motion artifacts lies in mechanical disturbances at the electronics-skin interfaces.

Here, we present the ultra-conformal, customizable, and deformable drawn-on-skin (DoS) electronics platform, which is robust to motion and can provide point-of-care therapy. Compared to existing wearable and/or printed bioelectronics fabricated based on dedicated equipment, DoS electronics has numerous advantages including: simple fabrication without dedicated equipment, ability to deposit electronic materials to dynamic surfaces, capability to construct active electronics, multifunctionality of devices and sensors, immunity to motion artifacts without the need for additional hardware or computation, which offers an unprecedented solution to the long-standing challenge in the bioelectronics field, and customizability for personalized point-of-care treatment. Specifically, DoS electronics is created by liquid functional inks drawn into stencils using ballpoint pens directly on human skin. Upon drawing, an ultra-conformal, robust, and stretchable interface that is immune to motion is formed between DoS electronics and skin. Example DoS devices, such as thin-film transistors, strain sensors, temperature sensors, heaters, skin hydration sensors, and electrophysiological (EP) sensors have been developed with qualities of skin textured surface, curvilinear shape, and mechanical deformability. A wireless electrocardiogram (ECG) monitoring system combined with DoS EP sensors demonstrates daily and clinical usages. By comparing the DoS EP sensors with hospital-grade gel electrodes, and ultrathin serpentine mesh electrodes, we found that DoS electronics has multiple advantages, such as stable performance in the presence of sweat, reliable capture of EP signals over a long duration, strong adherence to the skin, and immunity to motion artifacts during sensing. Additionally, DoS electronics combined with electrical stimulation demonstrates accelerated healing of skin wounds.