Bioinspired Environment-Adaptable and Ultrasensitive Multifunctional Electronic Skin for Human Healthcare and Robotic Sensations.

Multifunctional electronic skins (e-skins) that can sense various stimuli have demonstrated increasing potential in many fields. However, most e-skins are human-oriented that cannot work in hash environments such as high temperature, underwater, and corrosive chemicals, impairing their applications, especially in human-machine interfaces, intelligent machines, robotics, and so on. Inspired by the crack-shaped sensory organs of spiders, an environmentally robust and ultrasensitive multifunctional e-skin is developed. By developing a polyimide-based metal crack-localization strategy, the device has excellent environment adaptability since polyimide has high thermal stability and chemical durability. The localized cracked part serves as an ultrasensitive strain sensing unit, while the non-cracked serpentine part is solely responsible for temperature. Since the two units are made of the same material and process, the signals are decoupled easily. The proposed device is the first multifunctional e-skin that can be used in harsh environments, therefore is of great potential for both human and robot-oriented applications.

Acoustofluidic-based microscopic examination for automated and point-of-care urinalysis.

Urinalysis is a heavily used diagnostic test in clinical laboratories; however, it is chronically held back by urine sediment microscopic examination. Current instruments are bulky and expensive to be widely adopted, making microscopic examination a procedure that still relies on manual operations and requires large time and labor costs. To improve the efficacy and automation of urinalysis, this study develops an acoustofluidic-based microscopic examination system. The system utilizes the combination of acoustofluidic manipulation and a passive hydrodynamic mechanism, and thus achieves a high throughput (1000 µL min-1) and a high concentration factor (95.2 ± 2.1 fold) simultaneously, fulfilling the demands for urine examination. The concentrated urine sample is automatically dispensed into a hemocytometer chamber and the images are then analyzed using a machine learning algorithm. The whole process is completed within 3 minutes with detection accuracies of erythrocytes and leukocytes of 94.6 ± 3.5% and 95.1 ± 1.8%, respectively. The examination outcome of urine samples from 50 volunteers by this device shows a correlation coefficient of 0.96 compared to manual microscopic examination. Our system offers a promising tool for automated urine microscopic examination, thus it has potential to save a large amount of time and labor in clinical laboratories, as well as to promote point-of-care urine testing applications in and beyond hospitals.

A nanonewton-scale biomimetic mechanosensor.

Biomimetic mechanosensors have profound implications for various areas, including health care, prosthetics, human‒machine interfaces, and robotics. As one of the most important parameters, the sensitivity of mechanosensors is intrinsically determined by the detection resolution to mechanical force. In this manuscript, we expand the force detection resolution of current biomimetic mechanosensors from the micronewton to nanonewton scale. We develop a nanocrack-based electronic whisker-type mechanosensor that has a detection resolution of 72.2 nN. We achieve the perception of subtle mechanical stimuli, such as tiny objects and airflow, and the recognition of surface morphology down to a 30 nm height, which is the finest resolution ever reported in biomimetic mechanosensors. More importantly, we explore the use of this mechanosensor in wearable devices for sensing gravity field orientation with respect to the body, which has not been previously achieved by these types of sensors. We develop a wearable smart system for sensing the body's posture and movements, which can be used for remote monitoring of falls in elderly people. In summary, the proposed device offers great advantages for not only improving sensing ability but also expanding functions and thus can be used in many fields not currently served by mechanosensors.