Project Overview

NIRT: C-MEMS/C-NEMS for Miniature Biofuel Cells

# 0709085
Marc Madou (Principal Investigator)
Leonidas Bachas (Co-Principal Investigator)
Sylvia Daunert (Co-Principal Investigator)
Chunlei Wang (Co-Principal Investigator)

In recent years, the quest for alternative sources that can autonomously power bioMEMS devices, especially those geared for in vivo applications, such as monitoring and drug delivery, has been the focus of research by scientists and engineers as new power sources will prove critical for the advancement of the field. Current batteries are still less than optimal and often present drawbacks related to safety, reliability and scalability. An ideal power source for implantable devices should take advantage of natural compounds present in the body of an individual and use them as fuel to produce power in a continuous and reproducible manner, as long as the patient's physiological functions remain steady. Biofuel cells, which are capable of converting biochemical energy into electrical energy, have been deemed as a potential solution to the drawbacks presented by conventional batteries, but the power density and operational lifetime requirements for implanted devices have not been met yet. To that end, we propose to integrate genetically engineered catalytic proteins and carbon-based 3 dimensional (3D) MEMS/NEMS structures to create new biofuel cells. The biofuel cell electrode surfaces, especially fractal electrode array, presents significantly increased surface area as compared to traditional architecture, increasing the biocatalyst loading capacity considerably for high power throughput. The genetically engineered enzymes inherently increase enzyme stability, consequently increasing biofeul cell lifetime. The scaled fractal electrode surface plays a role in wiring the enzymes to the biofuel cell anode, which increases the electron transfer efficiency from the enzyme to the electrode for an increase in the overall performance of the biofuel cells. Furthermore, C-MEMS/C-NEMS architectures will enable the reproducible fabrication of low cost carbon-based electrode structures.

We envision that this project will have an impact on the MEMS, NEMS and bioMEMS communities. Given that C-MEMS/NEMS technologies can be used in a number of fields as a substitute for siliconbased devices, the proposed technology should find applications not only in energy-related areas, such as biofuel cells, micro-batteries and super capacitors, but also in others, such as biosensing, drug delivery and actuators. The C-MEMS/NEMS approach gives the development engineers unprecedented freedom in the design and manufacture of high surface area conductive structures through the use of new materials and innovative fabrication techniques. The development of biofuel cells based on producing high aspect ratio 3D carbon structures in the mm to nm range by integrating ?top-down? and ?bottom-up? processing approaches and combining biological components with MEMS/NEMS structures should present advantages over traditionally used Si-based materials. Moreover, this could start a trend in the lithographic patterning of materials other than Si. Further, the proposed technologies could also have an impact on other industries and on the end-users. For example, the point-of-care diagnostic market, including implantable biosensors that track blood glucose levels and deliver insulin, is approximately a $7 billion to $8 billion market growing at around 10% per annum. Since our biofuel cells are ideal for use in miniaturized medical devices, we expect that they could have an impact both in in vivo as well as in vitro diagnostics and point-of-care situations.

The PIs have a well-established productive collaboration that has resulted in a good number of joint publications, grants, and advising of graduate and postdoctoral students. This project will further enhance the current interdisciplinary and collaborative effort of the groups of Dr. Madou at UCI, Dr. Wang at FIU and Drs. Bachas and Daunert at UK. The proposed collaborative research will allow us to combine ?bottom-up? biotechnology with ?top-down? micro/nanomanufacturing techniques for bio MEMS/NEMS applications. Such work will foster interdisciplinary interactions and will train students with different backgrounds, i.e., chemical/materials engineering, mechanical engineering, electrical engineering, and chemistry, in the broad areas of micro/nano fabrication of novel biomedical sensing devices and high capacity miniaturized power sources. Workshops and outreach programs will be conducted to broadly disseminate the results of this work and raise awareness to students (undergraduates and K-12) and the general public in bioMEMS and Nanobiotechnology. Moreover, this project broadens the participation of women in multidisciplinary science and engineering.

Source: NSF