Flexible large-area ultrasound arrays for medical applications made using embossed polymer structures.

With the huge progress in micro-electronics and artificial intelligence, the ultrasound probe has become the bottleneck in further adoption of ultrasound beyond the clinical setting (e.g. home and monitoring applications). Today, ultrasound transducers have a small aperture, are bulky, contain lead and are expensive to fabricate. Furthermore, they are rigid, which limits their integration into flexible skin patches. New ways to fabricate flexible ultrasound patches have therefore attracted much attention recently. First prototypes typically use the same lead-containing piezo-electric materials, and are made using micro-assembly of rigid active components on plastic or rubber-like substrates. We present an ultrasound transducer-on-foil technology based on thermal embossing of a piezoelectric polymer. High-quality two-dimensional ultrasound images of a tissue mimicking phantom are obtained. Mechanical flexibility and effective area scalability of the transducer are demonstrated by functional integration into an endoscope probe with a small radius of 3 mm and a large area (91.2×14 mm2) non-invasive blood pressure sensor.

Touchscreen tags based on thin-film electronics for the Internet of Everything.

Capacitive touchscreens are increasingly widespread, featuring in mobile phones and tablets, as well as everyday objects such as cars and home appliances. As a result, the interfaces are uniquely placed to provide a means of communication in the era of the Internet of Everything. Here we show that commercial touchscreens can be used as reader interfaces for capacitive coupled data transfer. The transfer of data to the touchscreen is achieved using a 12-bit thin-film capacitive radio frequency identification tag powered by a thin-film battery or a thin-film photovoltaic cell that converts light from the screen. The thin-film integrated circuit has a 0.8 cm2 on-chip monolithic antenna, employs 439 transistors, and dissipates only 31 nW of power at a supply voltage of 600 mV. The chip has an asynchronous data rate of up to 36 bps, which is limited by the touchscreen readout electronics.