An on-demand microfluidic hydrogen generator with self-regulated gas generation and self-circulated reactant exchange with a rechargeable reservoir

  • L. Zhu
  • N. Kroodsma
  • J. Yeom
  • J. L. Haan
  • M. A. Shannon
  • D. D. MengEmail author
Research Paper


This article introduces an on-demand microfluidic hydrogen generator that can be integrated with a micro-proton exchange membrane (PEM) fuel cell. The catalytic reaction, reactant circulation, gas/liquid separation, and autonomous control functionalities are all integrated into a single microfluidic device. It generates hydrated hydrogen gas from an aqueous ammonia borane solution which is circulated and exchanged between the microfluidic reactor and a rechargeable fuel reservoir without any parasitic power consumption. Ammonia borane is chosen instead of sodium borohydride because of its faster hydrogen generation rate, higher hydrogen storage capability, stability, and better catalyst durability. The self-circulation of the ammonia borane solution was achieved using directional growth and selective venting of hydrogen bubbles in micro-channels, which leads to agitation and addition of fresh solution without consumption of electrical power. The self-regulation mechanism ensures that hydrogen can be supplied to a fuel cell according to the exact demand of the current output of the fuel cell. The circulation flow rate of ammonia borane solution is also automatically regulated by the venting rate of hydrogen at the gas outlet. Design, fabrication, and testing results of a prototype system are described. The hydrogen generator is capable of generating hydrogen gas at a maximum rate of 0.6 ml/min (2.1 ml/min cm2) and circulating aqueous ammonia borane at a maximum flow rate of ~15.7 μl/min. The device has also been connected with a micro-PEM fuel cell to demonstrate the feasibility of its practical applications in a high-impedance system.


Micro-fuel cell Hydrogen generator Microfluidic Ammonia borane Self-circulation Self-regulation 



This research is supported by Michigan Tech Research Excellence Fund. Micro-Nano-Mechanical Systems Laboratory at the University of Illinois at Urbana-Champaign provided the use of the microfabrication facility.


  1. Brockman A, Zheng Y, Gore J (2010) A study of catalytic hydrolysis of concentrated ammonia borane solutions. Int J Hydrogen Energy 35(14):7350–7356CrossRefGoogle Scholar
  2. Cowey K, Green KJ, Mepsted GO, Reeve R (2004) Portable and military fuel cells. Curr Opin Solid State Mater Sci 8(5):367–371CrossRefGoogle Scholar
  3. Dai HB, Gao LL, Liang Y, Kang XD, Wang P (2010a) Promoted hydrogen generation from ammonia borane aqueous solution using cobalt-molybdenum-boron/nickel foam catalyst. J Power Sources 195(1):307–312CrossRefGoogle Scholar
  4. Dai HB, Kang XD, Wang P (2010b) Ruthenium nanoparticles immobilized in montmorillonite used as catalyst for methanolysis of ammonia borane. Int J Hydrogen Energy 35(19):10317–10323CrossRefGoogle Scholar
  5. Demirci UB, Miele P (2009) Sodium borohydride versus ammonia borane, in hydrogen storage and direct fuel cell applications. Energy Environ Sci 2(6):627–637CrossRefGoogle Scholar
  6. Gervasio D, Tasic S, Zenhausern F (2005) Room temperature micro-hydrogen-generator. J Power Sources 149:15–21CrossRefGoogle Scholar
  7. Hoeppner K, Hahn R, Reichl H, Esashi M, Tanaka S (2009) Fabrication and evaluation of a NaBH4 hydrogen microreactor assembled by triple stack glass bonding. In: PowerMEMS 2009, Washington, DC, December 14, 2009, pp 29–32Google Scholar
  8. Kim T (2009) Micro reactor for hydrogen generation from sodium borohydride. In: PowerMEMS, Washington DC, December 1–4, 2009, pp 33–36Google Scholar
  9. Kim J-H, Kim K-T, Kang Y-M, Kim H-S, Song M-S, Lee Y-J, Lee PS, Lee J-Y (2004) Study on degradation of filamentary Ni catalyst on hydrolysis of sodium borohydride. J Alloys Compd 379(1–2):222–227CrossRefGoogle Scholar
  10. Kojima Y, Suzuki K, Fukumoto K, Sasaki M, Yamamoto T, Kawai Y, Hayashi H (2002) Hydrogen generation using sodium borohydride solution and metal catalyst coated on metal oxide. Int J Hydrogen Energy 27(10):1029–1034CrossRefGoogle Scholar
  11. Kojima Y, Suzuki K, Fukumoto K, Kawai Y, Kimbara M, Nakanishi H, Matsumoto S (2004) Development of 10 kW-scale hydrogen generator using chemical hydride. J Power Sources 125(1):22–26CrossRefGoogle Scholar
  12. Kundu A, Jang JH, Gil JH, Jung CR, Lee HR, Kim SH, Ku B, Oh YS (2007) Micro-fuel cells—current development and applications. J Power Sources 170(1):67–78CrossRefGoogle Scholar
  13. Liu BH, Li ZP (2009) A review: hydrogen generation from borohydride hydrolysis reaction. J Power Sources 187(2):527–534CrossRefGoogle Scholar
  14. Lu Y, Wang H, Liu Y, Xue Q, Chen L, He M (2007) Novel microfibrous composite bed reactor: high efficiency H2 production from NH3 with potential for portable fuel cell power supplies. Lab Chip 7:133–140CrossRefGoogle Scholar
  15. Meng DD, Kim CJ (2008) Micropumping of liquid by directional growth and selective venting of gas bubbles. Lab Chip 8(6):958–968CrossRefGoogle Scholar
  16. Meng DD, Kim CJ (2009) An active micro-direct methanol fuel cell with self-circulation of fuel and built-in removal of CO2 bubbles. J Power Sources 194(1):445–450CrossRefGoogle Scholar
  17. Meng DD, Kim J, Kim C-J (2006) A degassing plate with hydrophobic bubble capture and distributed venting for microfluidic devices. J Micromech Microeng 16:419–424CrossRefGoogle Scholar
  18. Metin O, Ozkar S (2009) Hydrogen generation from the hydrolysis of ammonia-borane and sodium borohydride using water-soluble polymer-stabilized cobalt(0) nanoclusters catalyst. Energy Fuels 23(7):3517–3526CrossRefGoogle Scholar
  19. Mitrovski SM, Nuzzo RG (2006) A passive microfluidic hydrogen-air fuel cell with exceptional stability and high performance. Lab Chip 6:353–361CrossRefGoogle Scholar
  20. Moghaddam S, Pengwang E, Masel RI, Shannon MA (2008) A self-regulating hydrogen generator for micro fuel cells. J Power Sources 185(1):445–450CrossRefGoogle Scholar
  21. Morse JD (2007) Micro-fuel cell power sources. Int J Energy Res 31(6–7):576–602CrossRefGoogle Scholar
  22. Muthukumar P, Maiya MP, Murthy SS (2005) Experiments on a metal hydride-based hydrogen storage device. Int J Hydrogen Energy 30(15):1569–1581CrossRefGoogle Scholar
  23. Ni M, Leung DYC, Leung MKH (2007) A review on reforming bio-ethanol for hydrogen production. Int J Hydrogen Energy 32(15):3238–3247CrossRefGoogle Scholar
  24. Oronzio R, Monteleone G, Pozio A, De Francesco M, Galli S (2009) New reactor design for catalytic sodium borohydride hydrolysis. Int J Hydrogen Energy 34(10):4555–4560CrossRefGoogle Scholar
  25. Pakzad SN, Fenves GL, Kim S, Culler DE (2008) Design and implementation of scalable wireless sensor network for structural monitoring. J Infrastruct Syst 14(1):89–101CrossRefGoogle Scholar
  26. Park C, Chou PH, Bai Y, Matthews R, Hibbs A (2006) An ultra-wearable, wireless, low power ECG monitoring system. In: IEEE BioCAS 2006, London, UK, November 29–December 1, 2006, pp 241–244Google Scholar
  27. Paust N, Litterst C, Metz T, Eck M, Ziegler C, Zengerle R, Koltay P (2009) Capillary-driven pumping for passive degassing and fuel supply in direct methanol fuel cells. Microfluid Nanofluid 7(4):531–543CrossRefGoogle Scholar
  28. Pinto A, Falcao DS, Silva RA, Rangel CM (2006) Hydrogen generation and storage from hydrolysis of sodium borohydride in batch reactors. Int J Hydrogen Energy 31(10):1341–1347CrossRefGoogle Scholar
  29. Pozio A, De Francesco M, Monteleone G, Oronzio R, Galli S, D’Angelo C, Marrucci M (2008) Apparatus for the production of hydrogen from sodium borohydride in alkaline solution. Int J Hydrogen Energy 33(1):51–56CrossRefGoogle Scholar
  30. Qian F, Baum M, Gu Q, Morse DE (2009) A 1.5 μL microbial fuel cell for on-chip bioelectricity generation. Lab Chip 9:3076–3081CrossRefGoogle Scholar
  31. Rapolu P (2007) Capillary effect on two-phase flow resistance in microchannels. M.S. thesis, University of CincinnatiGoogle Scholar
  32. Richardson BS, Birdwell JF, Pin FG, Jansen JF, Lind RF (2005) Sodium borohydride based hybrid power system. J Power Sources 145(1):21–29CrossRefGoogle Scholar
  33. Rosi NL, Eckert J, Eddaoudi M, Vodak DT, Kim J, O’Keeffe M, Yaghi OM (2003) Hydrogen storage in microporous metal-organic frameworks. Science 300(5622):1127–1129CrossRefGoogle Scholar
  34. Sakintuna B, Lamari-Darkrim F, Hirscher M (2007) Metal hydride materials for solid hydrogen storage: a review. Int J Hydrogen Energy 32(9):1121–1140CrossRefGoogle Scholar
  35. Strizki M, Shah S (2002) Self-regulating hydrogen generator. USA Patent 6939529Google Scholar
  36. Varady MJ, McLeod L, Meacham JM, Degertekin FL, Fedorov AG (2007) An integrated MEMS infrastructure for fuel processing: hydrogen generation and separation for portable power generation. J Micromech Microeng 17(9):S257–S264CrossRefGoogle Scholar
  37. Wainright JS, Savinell RF, Liu CC, Litt M (2003) Microfabricated fuel cells. Electrochim Acta 48(20–22):2869–2877CrossRefGoogle Scholar
  38. Xia ZT, Chan SH (2005) Feasibility study of hydrogen generation from sodium borohydride solution for micro fuel cell applications. J Power Sources 152(1):46–49CrossRefGoogle Scholar
  39. Yang J, Sudik A, Wolverton C, Siegel DJ (2010) High capacity hydrogen storage materials: attributes for automotive applications and techniques for materials discovery. Chem Soc Rev 39(2):656–675CrossRefGoogle Scholar
  40. Yang JG, Cheng FY, Liang J, Chen J (2011) Hydrogen generation by hydrolysis of ammonia borane with a nanoporous cobalt-tungsten-boron-phosphorus catalyst supported on Ni foam. Int J Hydrogen Energy 36(2):1411–1417CrossRefGoogle Scholar
  41. Yeom J, Shannon MA (2010) Detachment lithography of photosensitive polymers: a route to fabricating three-dimensional structures. Adv Funct Mater 20(2):289–295CrossRefGoogle Scholar
  42. Yeom J, Jayashree RS, Rastogi C, Shannon MA, Kenis PJA (2006) Passive direct formic acid microfabricated fuel cells. J Power Sources 160(2):1058–1064CrossRefGoogle Scholar
  43. Zhang Q, Smith G, Wu Y, Mohring R (2006) Catalytic hydrolysis of sodium borohydride in an auto-thermal fixed-bed reactor. Int J Hydrogen Energy 31(7):961–965CrossRefGoogle Scholar
  44. Zhang JS, Zheng Y, Gore JP, Mudawar I, Fisher TS (2007) 1 kW(e) sodium borohydride hydrogen generation system part II: reactor modeling. J Power Sources 170(1):150–159CrossRefGoogle Scholar
  45. Zhu L, Kim D, Kim H, Masel RI, Shannon MA (2008a) Hydrogen generation from hydrides in millimeter scale reactors for micro proton exchange membrane fuel cell applications. J Power Sources 185(2):1334–1339CrossRefGoogle Scholar
  46. Zhu L, Lin KY, Morgan RD, Swaminathan VV, Kim HS, Gurau B, Kim D, Bae B, Masel RI, Shannon MA (2008b) Integrated micro-power source based on a micro-silicon fuel cell and a micro electromechanical system hydrogen generator. J Power Sources 185(2):1305–1310CrossRefGoogle Scholar
  47. Zhu L, Meng DD, Kroodsma N, Yeom J, Shannon MA (2009) An integrated microfluidic self-regulating and self-circulating hydrogen generator for fuel cells. In: Technical digest. The 15th international conference on solid-state sensors, actuators and microsystems, Denvor, Colorado, June 21–25, 2009, pp 652–655Google Scholar
  48. Zhu L, Swaminathan V, Gurau B, Masel RI, Shannon MA (2009b) An onboard hydrogen generation method based on hydrides and water recovery for micro-fuel cells. J Power Sources 192(2):556–561CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • L. Zhu
    • 1
  • N. Kroodsma
    • 2
  • J. Yeom
    • 3
  • J. L. Haan
    • 4
  • M. A. Shannon
    • 3
  • D. D. Meng
    • 2
    Email author
  1. 1.Department of Mechanical EngineeringIndiana University–Purdue University IndianapolisIndianapolisUSA
  2. 2.Department of Mechanical Engineering and Engineering MechanicsMichigan Technological UniversityHoughtonUSA
  3. 3.Department of Mechanical Science and EngineeringUniversity of Illinois at Urbana-ChampaignUrbanaUSA
  4. 4.Department of ChemistryTowson UniversityTowsonUSA

Personalised recommendations