Flexible array sensor

Keywords— Wireless sensor network. Flexible array sensor. Radio frequency sputtering. Screen-printing, pH sensitivity. 

According to the mention above, the primary researches focused on the attempt to use the NI wireless sensor network module for V-T measurement system. And the flexible array sensor was applied to detect the response voltage for pH buffer solution, in this study. 

The current-voltage (I-V) measurement system is composed of Keithley 236 Semiconductor Parameter Analyzer and a readout circuit of n-MOSFET. The sensitivity and linearity of flexible array sensor measured in the concentrations between pHl and pH 13 at room temperature (25 °C) were represented in Table 1. The ranges of sensitivity and linearity were from 49.77 mV/ pH to 56.74 mV/pH and from 0.994 to 0.998, respectively. At present, the pH array sensors have been fabricated successfully and applied to I-V measurement system. 

The wireless sensor network measurement system with flexible array sensor has been presented. Then the Lab-VIEW software was based on a personal computer and the measurement data can be acquired, processed, analyzed, and presented via wireless sensor network. And according to the experimental results, the sensitivities and linearity of flexible array sensor measured by V-T measurement system with DAQ card or WSN system are excellent. Hence, they can replace the conventional and expensive of instrument for V-T measurement system. 

Finally, the measurement curve and interface of WSN measurement system is shown in Fig. 6. And the sensitivity and linearity of flexible array sensor in the concentrations between pHl and pH 13 were represented in Table 1. The sensitivities and the linearities were 51.75 mV/ pH to 53.39 mV/pH and 0.967 to 0.990, respectively. In order to prove that the NI-WSN device was feasible for pH measurement, the same sensor was used for DAQ card device, and the sensitivity and linearity of flexible array sensor in the concentrations between pHl and pH13 were represented in Table 1. The sensitivities and linearity were from 51.86 mV/ pH to 53.80 mV/pH and from 0.998 to 0.999, respectively. According to above results, the NI-WSN device was feasible for hydrogen ion detection. 

McAlpine, M. C. Ahmad, H. Wang, D. Heath, J. R. 2007. Highly ordered nanowire arrays on plastic substrates for ultrasensitive flexible chemical sensors. Nature Mater. 5 379-384. 

Mayr T, Abel T, Enko B, Borisov S, Konrad C, Kostler S, Lamprecht B, Sax S, List EJW, Klimant I (2009) A planar waveguide optical sensor employing simple light coupling. Analyst 134 1544-1547 McAlpine MC, Ahmad H, Wang D, Heath JR (2007) Highly ordered nanowire arrays on plastic substrates for ultrasensitive flexible chemical sensors. Nat Mater 6 379-384... 

Zadeh, E.G.,Rajagopalan, S., Sawan, M., 2006. Flexible biochemical sensor array for laboratory-on-chip applications. In International Workshop on Computer Architecture for Machine Perception and Sensing, 2006 (CAMP 2006). IEEE, New York, NY, USA, pp. 65-66. 

Wireless Sensor Network for Flexible pH Array Sensor... 

Abstract— In this study, a wireless sensor network (WSN) for flexible pH array sensor has been developed by virtual software of National Instrument (NI) Laboratory Virtual Instrument Engineering Workbench (LabVIEW). The measurement data were received from measurement node and sent to a gateway connecting with computer through WSN. The WSN has been combined successfully with flexible pH array sensor. And the sensitivity and linearity of the flexible pH array sensor received through WSN are 53.39 mV/pH and 0.990 in pH concentrations between pHl and pH13 at room temperate (25 C), respectively. Therefore, the developed WSN can be applied to the flexible pH array sensor practically. 

Chou J C, Chen C C (2009) Weighted data fusion for flexible pH sensors array. Biomed. Eng. Appl. Basis Commun. 21 365-369... 

Fabrication of Base Sensors For fabrication of redundant sensor arrays on metal or flexible insulating substrates, processes used in the semiconductor industry can be utilized as shown in Figure 8.2.44,45 Photolithography, wet etch, dry etch, sputtering, and evaporation are a few processes that have been used.46,47 The techniques described in this section can be used many times on the same sample to lead to numerous metals (or different electrodes) being fabricated on the same substrate, which can then be implanted in vivo. 

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