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Graphene nanowalls (GNWs) exhibit outstanding optoelectronic properties due to their peculiar structure, which makes them a great potential in infrared (IR) detection. Herein, a novel IR detector that is composed of polydimethylsiloxane (PDMS) and designed based on GNWs is demonstrated. Such detector possesses an anomalous temperature coefficient of resistance of 180% K −1 and a relatively high change rate of current (up to 16%) under IR radiation from the human body. It primarily attributes to the ultra-high IR absorption of the GNWs and large coefficient of thermal expansion of PDMS. In addition, the GNW/PDMS device possesses excellent detection performance in the IR region with a responsivity of ~1.15 mA W , which is one or two orders of magnitude larger than that of the traditional carbon-based IR detectors. The significant performance indicates that the GNW/PDMS-based devices reveal a novel design concept and promising applications for the future new-generation IR photodetectors.

Flexible and wearable humidity sensors play a vital role in daily point-of-care diagnosis and noncontact human-machine interactions. However, achieving a facile and high-speed fabrication approach to realizing flexible humidity sensors remains a challenge. In this work, a wearable capacitive-type Ga 2 O 3 /liquid metal-based humidity sensor is demonstrated by a one-step laser direct writing technique. Owing to the photothermal effect of laser, the Ga 2 O 3 -wrapped liquid metal particles can be selectively sintered and converted from insulative to conductive traces with a resistivity of 0.19 Ω•cm, while the untreated regions serve as active sensing layers in response to moisture changes. Under 95% relative humidity, the humidity sensor displays a highly stable performance along with rapid response and recover time. Utilizing these superior properties, the Ga 2 O 3 /liquid metal-based humidity sensor is able to monitor human respiration rate, as well as skin moisture of the palm under different physiological states for healthcare monitoring.

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 In nanofabrication point of view, fabricating a pattern structured with high-aspect ratio nanoantennas and distribution in large area is quite chanllenge. Especially for the structures being used as biochemistry sensors, the sharp nanoantennas with high-aspect ratio is one of an important features. It can form numerous tiny hot spots as small as 50 nm for directional radiation and beaming which is evidenced by our probing results from near-field scanning optical microscope. A novel metasurface-based nanoantennas array fabricated using a technique of heavy ion tracking is introduced in this paper. The technique has advantages of large area patterning, high aspect ratio of the single pillar, controllable length, and multi-choice of materials etc.Fabrication process, numerical calculation and optical near-field characterization of the structure are presented.Performing as a biochemistry sensor, sensitivity of 137 nm/RIU is obtained for sensing alcohol on the basis of spectroscopy results. Our theoretical and experimental results demonstrate that this structure is capbale of acting as biochemistry sensors for immunoassay and cell/molecular spectrocopy.