No abstract

C 60 and single-layer MoS 2 nanocomposites were facilely prepared via a combined solvent transfer and surface deposition (STSD) method by templating C 60 aggregates on 2D MoS 2 nanosheets to construct hybrid van der Waals heterojunctions. The electronic property of the hybrid nanomaterials was investigated in a direct charge transport diode device configuration of ITO/C 60 −MoS 2 nanocomposites/Al; rewritable nonvolatile resistive switching with low SET/RESET voltage (∼3 V), high ON/OFF resistance ratio (∼4 × 10 3 ), and superior electrical bistability (>10 4 s) of a flash memory behavior was observed. This particular electrical property of C 60 −MoS 2 nanocomposites, not possessed by either C 60 or MoS 2 nanosheets, was supposed to be due to the efficiently established C 60 /MoS 2 p−n nanojunction, which controls the electron tunneling via junction barriers modulated by electric-field-induced polarization. Thus, our 2D templating method through STSD is promising to massively allocate van der Waals p−n heterojunctions in 2D nanocomposites, opening a window for important insights into the charge transport across the interface of organic/2D-semiconductors.

This paper presents an all-polymer flexible micromachined flow sensor using a carbon-black based conductive composite elastomer as a piezoresistor. The device is composed of an out-of-plane curved flow sensing element formed using a polyimide film. The conductive composite elastomer combines a low Young’s modulus (∼1.72 MPa) and a high piezoresistive gage factor (∼7.3), making it an ideal material for the sensing application. Moreover, the use of the polyimide film, which can be easily laser micromachined, as the material for device fabrication enables the use of planar micromachining techniques, which minimizes process complexities. The proposed fabrication sequence combines the benefits of the polymeric materials used, while simultaneously enabling a backside interconnect scheme for an array of devices, without additional processing steps. The backside interconnect scheme allows for flow field mapping with minimum interference due to the sensing circuitry. Individual sensors as small as 1.5 mm in length and 0.4 mm in width, with 70 µm wide and 20–50 µm thick piezoresistor lines, have been fabricated. Wind tunnel testing demonstrated sensitivities as high as 66Ω/(m s−1). The integration of polyimide films and conductive elastomers into a flow sensing device using the simple planar fabrication technologies discussed is suitable for reduced cost, large area sensor array development, and can also leverage traditional flexible circuit fabrication.

No abstract

No abstract