EAGER: Towards a Homeostatic Nanobio-Hybrid Mechanical System

Nature’s ability to balance degradation with self-repair enables long-lasting mechanically active structures. For example, the molecular motors responsible for the contraction of a heart muscle are replaced every few days, allowing the muscle to pump blood for a hundred years. In today’s engineered systems, moving parts age due to mechanical wear and fatigue and have to be replaced while the system is taken offline. The long-term goal of this EArly-concept Grant for Exploratory Research (EAGER) project is to create engineered systems which renew themselves at the molecular level. This award supports exploratory research into adding repair mechanisms to a nanoscale transport system. By demonstrating the feasibility of countering specific degradation processes with specific repair processes, the work will show that a long-lived system which maintains itself in a functional state could be constructed. The US economy will benefit significantly if the lifetime of machines and structures can be extended and interruptions in service can be avoided. The design of “living” engineered systems will also advance our understanding of the biological structures in our own bodies. The project will broaden the participation of underrepresented groups in engineering. Outreach activities will inspire a new generation of high school students to pursue an engineering education. Biological molecular motors enable the construction of active nanoscale transport systems with applications in biosensing, biocomputing and nanomanufacturing, where a cargo-carrying or functionalized microtubule is propelled by surface-adhere kinesin motor proteins. Past work has quantified the degradation mechanisms of microtubules due to the action of the surface-adhered kinesin motors propelling it forward. The goal of this project is to take the next step and to actively counteract specific degradation mechanisms. The primary microtubule degradation mechanisms of shrinking and breaking can be potentially counteracted by growth via polymerization and fusing of microtubule segments. Significant technical challenges in implementing these self-repair mechanisms exist and the feasibility of achieving a steady state where degradation and self-repair are balanced has to be determined. Specifically, the project will demonstrate that growth and fusing can be precisely quantified and controlled. The outcome of the project will be a potentially transformational transition towards “living” engineered systems, which self-repair, that is use active, energy-consuming processes to maintain their functional state at the molecular scale.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.