ABSTRACT：

    There has been much recent activity directed toward engineering devices powered by biological structures from the molecular to the tissue level. Since individual molecular motors provide only miniscule amounts of work, the actions of millions or more must be harnessed in parallel to result in significant activity in the macroscopic world. The prospects of exploiting natural massively parallel motor assemblies, such as muscle cells, are very attractive since the production, organization, and manipulation of the motors from nanometer to millimeter length scales are coordinated by complex biological molecular machinery refined over millions of years of natural selection. Engineering muscle cells onto microchips is an initial but critical step towards fabricating autonomous intelligent hybrid micromachines since cells have extremely elaborate ways of self-sustainment, regulation and assembly.

    The use of mature muscle tissues from animals on these devices is impractical and inefficient, as the tissues must be dissected and incorporated into each device by hand with crude interfaces between the biological tissues and inorganic materials. Integration of muscle with microfabricated structures would be optimally achieved through self-assembling muscle cells on MEMS. However, the unique anisotropic, structural, and contractile characteristics of muscle bundles complicate the construction of muscle-powered MEMS structures. Specifically, there exist three interrelated outstanding problems: 1) to spatially and selectively direct the growth and maturation of cells on microfabricated substrates, 2) to control the tight binding of differentiated muscle bundles with the surrounding mechanical structures, and 3) while maintaining the tight binding in specified locations, enable the cells and the resultant hybrid structure freedom to move.

    To address these problems, we have devised a novel system for the creation of self-assembled muscle-powered microdevices through the manipulation of material interfaces and phase. Two types of devices will be presented to illuminate the potential of this fabrication system. One type allows us to in situ characterize the mechanical properties of the muscle. The mechanical properties of the neonatal ventricular myocytes, such as substrate-induced stress (2-2.5 kPa) and Young’s Modulus (~40 kPa), have been directly measured. Another has resulted in the first self-assembled microrobots which move autonomously in response to the contraction of muscle bundles. Hybrid microrobots with the size of 160 μm can move at speeds of 10-50μm/s for more than 4 hours. A wide range of MEMS devices, electronic circuits, and patternable materials can be seamlessly integrated with a variety of cell types via our established system. The union of top-down MEMS fabricated structures with those synthesized, organized, and maintained by the bottom-up processes of biology could create devices with properties unattainable by either alone.

    Besides introducing my previous work, I will give a mini-review of state-of-art of Bio-nano/micro-technology and also explain my current research interests in this talk.

个人简历：

    席建忠，北京大学工学院，生物医学工程系特聘研究员。

教育经历:

博士  加州大学，洛杉矶分校，2002-2004, 生物力学，生物材料与组织工程

康奈尔大学，2000-2002, 生物工程与技术

硕士  清华大学，中国，1997-2000, 分子与细胞生物学

本科    北京理工大学，中国，1992-1997,  化学工程

工作经历：

2005.7-至今,       特聘研究员,北京大学工学院，生物医学工程系

2004.9-2005.6,     高级研究助理，加州大学洛杉矶分校(UCLA)　

       (期间获得美国Nebraska大学林肯分校Assistant Professor职位）

荣誉:

1. “2004 国家优秀自费留学生奖学金” ，中国教育部，2005年

2. “杰出博士毕业生”, 加州大学洛杉矶分校 (2004年)

3. “最佳学生／青年科研工作者” 国际材料研究学会，2004年春季大会