Fabrication of ZnO nanorods and Chitosan@ZnO nanorods on MEMS piezoresistive self-actuating silicon microcantilever for humidity sensing

Xu, Jiushuai; Bertke, Maik; Li, Xiaojing; Mu, Haibo; Zhou, Hao; Feng, Yuqing; Hamdana, Gerry; Schmidt, Angelika; Bremers, Heiko; Peiner, Erwin

doi:10.1016/j.snb.2018.06.017

Cited by 70 publications

(50 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The low-temperature CBD method is a simple facility, no-catalyst and low-cost process [2]. However, before the growth of ZnO NRs, an aqueous spin-coating method or sol-gel alkaline solution is essential for seed-layer (SL) coating, which are not compatible with MEMS fabrication [3]. In this paper, we report a CBD-based twosteps process, by using a DC sputtering/annealing (S/A) method for SL deposition.…”

Section: Introductionmentioning

confidence: 99%

Area-Selective Growth of Aligned ZnO Nanorod Arrays for MEMS Device Applications

Strempel

Zhou

et al. 2018

Eurosensors 2018

Self Cite

View full text Add to dashboard Cite

ZnO nanorods (NRs) arrays with good vertical alignment were selectively grown on microscale patterned surfaces by a MEMS-compatible, low-temperature chemical-bath deposition method (CBD). The direct-current (DC) sputtered and subsequently annealed ZnO seed-layer was found to have a crucial effect on the ZnO NRs growth. Depending on the pre-annealing temperature between 200 °C and 700 °C, which is compatible with our microcantilever fabrication process, diameters and area densities of the NRs of 60–99 nm and 17–27 µm−2 were observed, respectively, with the best alignment at 600 °C. A surface-area enlargement factor of 48 was achieved with respect to a ZnO layer indicating the potential of ZnO NRs arrays for MEMS applications, such as gas sensing.

show abstract

Section: Introductionmentioning

confidence: 99%

Area-Selective Growth of Aligned ZnO Nanorod Arrays for MEMS Device Applications

Strempel

Zhou

et al. 2018

Eurosensors 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…Dai et al also verified these observations by presenting the humidity sensing properties of chitosan-decorated ZnO-SWCNT (single-walled carbon nanotube) structures [19]. Xu et al increased the humidity sensing abilities of bare ZnO nanorods by four times by using a chitosan layer on top of ZnO nanorods [20].…”

Section: Introductionmentioning

confidence: 85%

UV-Enhanced Humidity Sensing of Chitosan–SnO2 Hybrid Nanowires

et al. 2020

View full text Add to dashboard Cite

The surface of SnO2 nanowires was functionalized by chitosan for the development of room-temperature conductometric humidity sensors. SnO2 nanowires were synthesized by the seed-mediated physical-vapor-deposition (PVD) method. Chitosan layers were deposited on top of the SnO2 nanowires by spin coating. Surface morphology, crystal structure, and optical properties of the synthesized hybrid nanostructure were investigated by scanning electron microscope, grazing incidence X-ray diffraction, and UV–Vis absorption measurements. During electrical conductivity measurements, the hybrid nanostructure showed unusual behavior towards various relative humidity (RH) concentrations (25%, 50%, 75%), under UV-light irradiation, and in dark conditions. The highest sensor responses were recorded towards an RH level of 75%, resulting in 1.1 in the dark and 2.5 in a UV-irradiated chamber. A novel conduction mechanism of hybrid nanowires is discussed in detail by comparing the sensing performances of chitosan film, SnO2 nanowires, and chitosan@SnO2 hybrid nanostructures.

show abstract

“…After that, a microcantilever with a dimension of 1000 µm in length, 170 µm in width and 50 ± 10 µm in thickness was obtained by back-and up-side etching using inductive-coupled plasma (ICP) cryogenic dry etching. Prior to the front-side etching, ZnO NRs were selectively and solely grown on microcantilever back surface using chemical bath deposition (CBD) on a DC-sputtered/annealed seed-layer [2]. Finally, chitosan SAMs on the ZnO NRs were deposited by dipping the cantilever into a 1% chitosan solution for 5 s. The chitosan solution was prepared by dissolving chitosan powder into 4% acetic solution and magnetic stirring for 24 h. For further details, we refer to [2,4].…”

Section: Microcantilever Fabricationmentioning

confidence: 99%

“…Therefore, owing to their good stability, high sensitivity, great integration capability, and excellent chemical and biocompatibility, ZnO nanostructures were used for various applications, including chemical sensors, solar cells, and photodetectors etc. In our past study, we reported the fabrication of ZnO nanorods (NRs) on the upside of microcantilevers and their humidity sensing performances [2]. In this paper, to investigate the relation of ZnO NRs and humidity sensing further, a ZnO nanofilm with a thickness of 200 nm and ZnO NRs of 1.5 µm and 6 µm in length were selectively deposited on the cantilevers' back surface as sensing material.…”

Section: Introductionmentioning

confidence: 99%

“…In this paper, to investigate the relation of ZnO NRs and humidity sensing further, a ZnO nanofilm with a thickness of 200 nm and ZnO NRs of 1.5 µm and 6 µm in length were selectively deposited on the cantilevers' back surface as sensing material. The newly developed fabrication method was based on our reported work [2,3]. Furthermore, ZnO NRs of different lengths were additionally coated with chitosan self-assembled monolayers (SAMs).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Silicon Microcantilevers with ZnO Nanorods/Chitosan-SAMs Hybrids on Its Back Surface for Humidity Sensing

Bertke

et al. 2018

Eurosensors 2018

Self Cite

View full text Add to dashboard Cite

This paper reports a piezoresistive silicon microcantilever-based gravimetric humidity sensor, where a ZnO nanofilm (200 nm) and ZnO nanorods (NRs) with different lengths (1.5 µm and 6 µm) modified with chitosan self-assembled monolayers (SAMs) are coated on the microcantilevers' back surface as the sensing material. Thanks to the new sensor design, the resonant frequency (RF) shifts induced by the mass adsorption on the high surface-area-to-volume ratio, hybrid-sensing nanostructure can be tracked directly by monitoring the output of the pdiffused full Wheatstone bridge. By depositing ZnO NRs and Chitosan SAMs, direct-reading microcantilevers with high repeatability, reliability and high sensitivity (15 Hz/%RH) can be achieved.

show abstract

Fabrication of ZnO nanorods and Chitosan@ZnO nanorods on MEMS piezoresistive self-actuating silicon microcantilever for humidity sensing

Cited by 70 publications

References 36 publications

Area-Selective Growth of Aligned ZnO Nanorod Arrays for MEMS Device Applications

Area-Selective Growth of Aligned ZnO Nanorod Arrays for MEMS Device Applications

UV-Enhanced Humidity Sensing of Chitosan–SnO2 Hybrid Nanowires

Silicon Microcantilevers with ZnO Nanorods/Chitosan-SAMs Hybrids on Its Back Surface for Humidity Sensing

Contact Info

Product

Resources

About