Mechanical Tester Driven by Surface Tension.

The measurement of in-plane mechanical properties, such as Young's modulus and strength, of thin and stretchable materials has long been a challenge. Existing measurements, including wrinkle instability and nano indentation, are either indirect or destructive, and are inapplicable to meshes or porous materials, while the conventional tension test fails to measure the mechanical properties of nanoscale films. Here, we report a technique to test thin and stretchable films by loading a thin film afloat via differential surface tension and recording its deformation.

Highly Transparent and Flexible Iontronic Pressure Sensors Based on an Opaque to Transparent Transition.

Human-computer interfaces, smart glasses, touch screens, and some electronic skins require highly transparent and flexible pressure-sensing elements. Flexible pressure sensors often apply a microstructured or porous active material to improve their sensitivity and response speed. However, the microstructures or small pores will result in high haze and low transparency of the device, and thus it is challenging to balance the sensitivity and transparency simultaneously in flexible pressure sensors or electronic skins.