Air Force Materiel Command REPORT DOCUMENTATION PAGE The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to the

more »

... partment of Defense, Executive Service Directorate (0704-0188). Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. enzymatic biofuel cells. Enzymatic biofuel cells hold great potential for providing flexible, compact energy to devices such as remote sensors and future miniature unmanned vehicles. However, current enzymatic biofuel cells suffer from low power densities (due to low enzyme concentrations) and short life-spans (due to low enzyme stability in vitro). These limitations derive largely from less-than-ideal techniques for immobilizing enzymes on electrodes. We propose to address these limitations by developing a new, highly stable self-assembling protein hydrogel platform for high-density enzyme immobilization on electrodes. The key features of the proposed protein hydrogel are: (1) conditional assembly of a highly stable protein hydrogel in response to the mixing of two soluble protein block copolymers, each functionalized by one fragment of a split intein, and (2) incorporation of 'docking station peptides' into the self-assembling protein copolymers which serve as anchors for high-affinity immobilization of enzymes end-fused to docking protein tags. 15. SUBJECT TERMS hydrogel, immobilization, enzyme, fuel cell, intein, protein, scaffold 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON Zhilei Chen a. REPORT b. ABSTRACT c. THIS PAGE 19b. TELEPHONE NUMBER (Include area code) 979-436-9404 Standard Form 298 (Rev. 8/98)