Microfluidics Based Air Pollutants Detection Device by Using Solvent Cast Method

Microfluidics Based Air Pollutants Detection Device by Using Solvent Cast Method

Sudhanshu Singh , Sangeeta Shekhawat1 and Dipesh D. Shukla2

1Department of Electronics and Communication Engineering

2Amity School of Engineering and Technology, Amity University Rajasthan, Jaipur

Abstract: In this work, we have mentioned the use of various types of polymer (i.e. conducting and nonconducting) in the area of pollutant detection. Through the innovative idea and design, one may able to detect the pollutants, and then after other follow up to be implemented for removal of the detected pollutants. Solvent cast method is chosen for the implementing the idea to make a fabricated and thin films on various substrate such as Mica, Glass, ITO and other conducting components. We actually combined the two technologies for the overall work. The first method was use of solvent cast method for well mixing of all components while second method was use of Microfluidics technology for creating micron level channel for sensing application of maximum types of hazardous gases. By using microscopic images and other characterization tools, we reached at the position where we may say with concrete results the innovation of such devices.

Keywords: Conductiong polymer, ITO, non conducting polymer.

1. INTRODUCTION

   As in the age of technological reforms, a lot of incorporation (inc) is added in the world for making sensor. As per the guide lines of world health organization, every inc are to be implemented pollution control mechanism in all type of waste such as liquid, solid and gas pollution. Through this work, we are trying to fabricate composite structure which may use for detecting such pollutant at early stage. Semi conducting materials are best suited for such kind of work [1]. For this work, we have used solvent cast method. In which, various polymers are being used with varying weight percentage of metal/non-metal oxides. Electronics nose is best example of such air quality kit [1]. In spite of these polymers and oxides compound, we also used varying dielectric, Ferro materials and others (bio molecule) [2].

2. MATERIALS AND METHODS

   1. PDMS and SU8

      Under the influence of temperature and environmental condition, lithographic method was used. Poly Di Methyl Siloxane was used as base materials for making detection channel. SU8 acts as photo resist which create binding of PDMS with the glass and other base substrate. Artificial neural network and artificial instruments are of such types [5].

   2. PDMS

      PDMS is the abbreviation of poly di methyl Siloxane. PDMS was purchased from Sigma Aldrich India. It is best fabricating chemical compound for making micron channel in Microfluidics research area. With the help of gold spin coater, gold coating of several microns are being done on glass substrate. Fig.1 shows the overview for such design. Digital connections are used for the design [6].

      Fig. 1 Glass reservoir made up from Gold spin coating

   3. SU8

      SU8 was purchased from Sigma Aldrich India. It is the code of positive resist which act as combinational platform for PDMS. There are two types of resist: positive and negative resist. Fig. 2 is the outcome from this fabrication tools and conceptual design. Graphite shows good results for this kind of work [7].

      Fig. 2. Channel fabricated channel by using PDMS and SU8

      Research Methodology Experimental Set ups

      This includes microfluidic based electrical circuit design clubbed with solvent cast method etc.

   4. Electrical Circuit Design

      Electrical circuit is demonstrated in Fig 3. In the electrical circuitry, we had applied varying range of frequency over variable voltages. The breadboard has been taken for the completion of the complete microfluidic electrical circuit. In the solvent cast method, we mixed and continued the formulation of composites by using various compounds (Fig 4). In the same follow ups, under various parameters change, we got various layer of composites structure.

      Fig.3 Electrical Circuit system for Microfluidics design

   5. Solvent Cast Method

      At 800-1200 rpm, 8-120 deg C and for approx. 40-70 minutes, all the chemical compositions were treated. Colloidal system has been used for the work [3]. Then drying of the thin films was done in hot air oven for 2-6 hours. This sensor design is best catalyst for air quality [4].

      Fig. 4 Schematic view of solvent cast method

      Under the heading of solvent cast method, various polymers and oxides combination are used. Measuring instrument such FRET is best suited for this work [8]. With due affect, micron level thin films are made on the glass and other base substrate. While under the heading of Microfluidics technology, with the use of PDMS and SU8, micron level channel is fabricated. Minimum GS are found in this design

      [9]. Through the fabricated micron level channel, the flow of solid waste is made done.

   6. Lithographic method

      Lithographic method is best technique for making fabrication channel. The sophisticated method consists of various instrumentation used in this system. Dipole review are also being covered [10]. Fig 5 shows the SAED image for Cadmium doped CdSe quantum dots.

      Fig. 5 SAED result of Cd doped CdSe quantum dots

      Fig. 6 shows the transmission electron microscopy images of CdSe and Cd quantum dots. Tunable effects are available for this work in the LR part [11]. Proper scattering of quantum dots is well shown in the TEM photo.

      Fig. 6 TEM result of scattered CdSe and Cd quantum dots

      TEM and SEM results show the nano particles and quantum dots of CdSe and Cd. The overall systems are being crossed through the micron level channel. Vertically Aligned Carbon Nano Tubes are best suited for battery which mimics the same work [12]. Due to the very high sensitiveness, the channel shows the presence of pollutants molecules presents in the flowing media, which may be solid, liquid and/or gases.

      With the help of Scherer formula, the dimensional relation with the frequency response can me sketched.

   7. UV Treatment

   In the lithographic method, after making the mask of PDMS-SU8, the exposure of Ultraviolet beams are done on this design for the removal of unwanted track of the channel. The main thing of UV implementation is the follow up the WHO and NIH rules of using UV i.e. under close chamber, to avoid extra, over and outer exposure of UV radiation in the environment i.e. human being and others. Fig 7 shows the fabricated channel. [13]

   Fig. 7. Micro channel fabrication by using lithographic method

3. RESULTS AND DISCUSSION

   1. Structural outcomes

      With the help of solvent cast method, the thin films of composites have been made. The level of films is in between 2-10µm. With the help of XRD instruments, we got the 2Theta

      = 28-32 deg at around 40% au. The XRD data varies from 10wt% to 90wt% of BaTiO3 with PMMA, incorporated with the TiO2. Fig 8 shows quantum dots of CdSe and Cd.

      Fig. 8. Quantum dots sample, by use of solvent cast method

      We got various results by using instrumental techniques such as capacitance, inductance, FWHM, impedance, zeta, electrical potential vs. temperature [14-15]. We also checked frequency dependency. 1-100 KHz frequencies are used from 20-200 deg c.

   2. Micrographical data

      After using and incorporating Microfluidics and solvent cast method, we are in the level of fabrication of channel. Fig 9 shows the fabricated channel under micron domains. Fig 10 shows scattered TEM result of Cd [6-18].

      Fig. 9. Micro channel fabrication by using soft lithographic method

      Fig. 10. TEM results of CdSe and Cd

   3. Fabrication results

   The fabricated results by using Microfluidics technology is mentioned in fig. 11, which may be best suitable for early level detection of air pollutants, by encapsulating compatible bio molecules and bio markers [19-20].

   Fig. 11. Micro channel fabrication

4. CONCLUSION

The main goal of making such air pollutant kit or device is to make it available for common media or society, which cannot bear so much expensive kit or device. PoC (The Point of Care), SoC (Ssystem on Chip), and LoC (Lab on Chip) are being developed by various companies. The price of such kit or device varies from 40-60 US dollar per kit[16-18], while by using this Microfluidics design, sandwiched with solvent cast method, these rate decreases. The rate of such detection kit will vary from 10-25 US Dollar. Apart from the price cut, the hand handling of such kit very easy to re calibrate and re used. Recycling, environmental friendly, user friendly and sustainability are also our prime concern for making such kits.

ACKNOWLEDGMENT

We would like to acknowledge Dr. B R Mehta for TEM facility and instrumental facilities used at Indian Institute of Technology Delhi, India.

REFERENCES

1. Wilson Z. Ray et al, Bioresorbable silicon electronic sensors for the brain, Nature, vol. 530, pp. 71-76, February 2016.

2. Zhiwu Han et al, Continuous directional water transport on the peristome surface of Nepenthes alata, Nature, vol. 1532, pp. 85-89, April 2016.

3. Bartosz A. Grzybowski et al, Colloidal assembly directed by virtual magnetic moulds, Nature, vol. 503, pp. 99-103, November 2013.

4. Katharine Sanderson , Artificial skins detect the gentlest touch, Nature, doi:10.1038/news.2010.463, 2010.

5. Yonggang Huang et al , Digital cameras with designs inspired by the arthropod eye, Nature, vol. 497, pp. 95-99, May 2013.

6. Jennifer A. Lewis et al , An integrated design and fabrication strategy for entirely soft, autonomous robots vol. 536, pp. 451-455, August 2016.

7. Subhrangsu Dey, S. Singh, S. M. Singh, Nikhil Rajput and Neeraj Kumar, The structural properties of BaTiO3: TiO2: PMMA composite films at room temperature, AIP Publishing, vol. 020154, pp. 1-8, May 2016.

8. Martin A. Schwartz et al , Measuring mechanical tension across vinculin reveals regulation of focal adhesion dynamics, vol 466|, pp. 263- 267, July 2010.

9. David J. Beebe et al, Controlled microfluidic interfaces, Nature, vol. 437, pp. 648-655, September 2005.

10. Si-Yang , Tunable and label-free virus enrichment for ultrasensitive virus detection using carbon nanotube arrays, Sci. Adv., vol. 2, no. 10, October 2016.

11. Ungyu Paik et al , Battery-free, stretchable optoelectronic systems for wireless optical characterization of the skin, Sci. Adv., vol. 2, no.8 2016

12. Sunil Kumar, Nitu Kumari, S.Singh, Tej Singh and Sanjay Jain, Doping studies of Tb (terbium) and Cu (copper) on CdSe nanorods, Colloids and Surfaces A: Physicochemical, vol. 389, pp. 1-5, 2011.

13. Franklin Bien et al , Graphene-Based Wireless Environmental Gas Sensor on PET Substrate, IEEE sensors journal, vol. 16, no. 12, June 2016.

14. Edward S. Kolesar , Miniature gas chromatography system realized using conventional vlsi fabrication techniques applied to quantifying toxic environmental pollutants, PG thesis, 2009

15. Joachim Goschnick et al, Air Quality Monitoring and Fire Detection With The Karlsruhe Electronic Micronose KAMINA , IEEE sensors journal, vol. 2, no. 3, June 2002.

16. RA Radhi et al, Dipole and Quadrupole Electroexcitations of the Isovector T= 1 ParticleHole States in 12C,- Chinese Physics Letters,vol. 23, no. 10, pp. 2699-2702, 2006.

17. A Babich et al, Effect of nut coke-sinter mixture on the blast furnace performance, , D Senk – ISIJ international,vol 51, pp. 35-358, 2011.

18. S Singh, L.M. Bharadwaj, S.K. Mahna, I Kaur and S. Garg, Study on Vertical Alignment of Carbon Nanotubes using AFM and SEM, Research Journal of Chemistry and Environment, vol. 16, issue 4, pp. 51-53, 2012.

19. A Giwa and S Karacan , Black-box modelling of ethyl acetate reactive packed distillation column AU Journal of Technology, vol. 15, issue 3, pp. 172-178, January 2012.

20. V Kumar et al, Defect correlated fluorescent quenching and electron phonon coupling in the spectral transition of Eu3+ in CaTiO3 for red emission in display application , Journal of Applied Physics,vol. 115, issue 193101,pp.1-14,2014.