3D-Printed Chemiresistive Sensor Array on Nanowire CuO/Cu₂O/Cu Heterojunction Nets

Abstract

In this work, the one-step three-dimensional (3D) printing of 20 nm nanowire (NW)-covered CuO/Cu 2 O/Cu microparticles (MPs) with diameters of 15−25 μm on the surface of the glass substrate forming an ordered net is successfully reported for the first time. 3D-printed Cu MP-based stripes formed nonplanar CuO/Cu 2 O/Cu heterojunctions after thermal annealing at 425 °C for 2 h in air and were fully covered with a 20 nm NW net bridging MPs with external Au contacts. The morphological, vibrational, chemical, and structural investigations were performed in detail, showing the high crystallinity of the NWs and 3D-printed CuO/Cu 2 O/Cu heterojunction lines, as well as the growth of CuO NWs on the surface of MPs. The gas-sensing measurements showed excellent selectivity to acetone vapor at an operating temperature of 350 °C with a high gas response about 150% to 100 ppm. The combination of the possibility of fast acetone vapor detection, low power consumption, and controllable size and geometry makes these 3D-printed devices ideal candidates for fast detection, as well as for acetone vapor monitoring (down to 100 ppm). This 3D-printing approach will pave a new way for many different devices through the simplicity and versatility of the fabrication method for the exact detection of acetone vapors in various atmospheres.

Additive Manufacturing as a Means of Gas Sensor Development for Battery Health Monitoring

“…For the preparation of the sensor devices a single-step, 3D-DIW approach reported by Siebert and co-workers [23] in a recent article was used (see Figure 1). The Cu-based stripes/traces prepared by DIW were covered with nanowire arrays with a size of~25 nm only after thermal annealing (TA) at 425 • C for 3 h in ambient temperature, thus forming CuO/Cu 2 O/Cu microparticles (MPs) bridge-lines.…”

“…For the preparation of the Cu-based stripes/traces set of sensors, copper microparticles of~20 µm in diameter were sonicated in H 2 O, then a powder of polyethylene oxide (M v~2 ,000,000, Sigma-Aldrich, St. Louis, MO, USA) was added at 20 • C (see representation Figure 1a). Stripes were printed from MPs prepared as reported in Table 1 and discussed in detail previously [23]. The stripes/traces were DIW as a single layer through a custom apparatus (see representation Figure 1b).…”

“…Based on that, 3D-DIW devices have attracted our consideration, due to their design potentiality as shown already e.g., for new strain sensing [21] or totally electronic components [22]. The progress in gas detecting and in 3D-DIW approaches will initiate larger capabilities to embody e.g., oxides directly onto multisensory or portable devices [23]. Previous reports claim that this 3D-approach will permit the assembly of multiple sensors through DIW for the precise sensing of specific vapors in various atmospheres, especially for battery safety.…”

Flexible wearable sensors - an update in view of touch-sensing

“…have also drawn much attention [46,47]. Besides, carbon nanomaterials-based inks (CNTs, graphene) show the printable and stretchable for flexible sensors [48][49][50][51].…”

In Situ Assembly of Ordered Hierarchical CuO Microhemisphere Nanowire Arrays for High‐Performance Bifunctional Sensing Applications

“…As an important p ‐type oxide with versatile properties, CuO nanowires have promising applications in molecular sensors for harmful vapor monitoring, [ 19–23 ] photodetectors, [ 24 ] field emitting devices, [ 25 ] energy storage devices, [ 26 ] etc. Previous studies indicate that the number and density of bridged nanowires play an important role in the device performance (i.e., response and power consumption of gas sensors), [ 7,27 ] therefore, a rational synthesis methodology is essential for constructing high‐performance devices.…”