CAREER: The exceptional biomechanics of legged locomotion in the microcosmos

这个学院早期职业发展(CALEAR)项目结合了生物实验、数学建模和物理模型，以揭示小型无脊椎动物腿部运动的表现能力和限制条件。从相对的尺度来看，地球上跑得最快的动物是最小的无脊椎动物。像甲虫、蟑螂和螨虫这样的生物能够以每秒数十到数百个身体长度的速度奔跑。这些在微观尺度上的非凡运动壮举是由强壮的四肢、健壮的脚部附着机制和弹性的外骨骼结构实现的，这些结构使这些生物的运动能力与它们较大的同类生物截然不同。然而，较小的生物还必须与令人难以置信的复杂和无结构的底物作斗争，这些底物可以施加等于或大于它们腿长的一步一步的高度变化。这项研究将开发复杂环境中腿部运动的一般原理，这可能有助于开发能够在非结构化环境中更有效地移动的新型腿部机器人。在研究目标的同时，将为K-12、本科生和学术专业人员开发教育经验，以便更好地将生命系统知识融入工程课程。这些活动包括与当地一所第一标题高中合作，为代表人数不足的学生提供资助的暑期研究体验。在学院一级，将实施课程开发、本科生和研究生的实践培训以及工程和生物学研究人员的跨学科讲习班。这些努力的总体目标是通过生命系统素养促进工程师和生物学家之间的参与、交流和合作。这项研究项目使用建模和实验来开发厘米级和毫米级生物体中腿部运动的新的几何和动态缩放原理。实验将在大小相差四个数量级的无脊椎动物身上进行(美国蟑螂、阿根廷蚂蚁和螨虫)。为了发展动物形态和自然底物之间的几何尺度原理，将开发一种新的实验底物扫描平台，以识别自然底物的三维形貌。为了研究力的产生和加速度的动态标度原理，将开发新的测力平台来测量微尺度步行运动中涉及的地面反作用力。这些实验将得到物理模型和计算模型的支持，以阐明腿部运动中动态和几何现象的标度规律。实验、建模和理论的结合将提高我们对微尺度腿部运动生物力学的理解。这项工作的总体目标是在微观到宏观尺度上对腿部运动的机制进行语境分析。这项工作的研究和教育目标是高度跨学科的。研究生和高中生将接受生物力学、物理和工程方面的广泛培训。学生将在机器人学、物理学和生物学会议上展示这些研究的结果，这些结果将发表在跨学科期刊上。因此，更广泛的影响包括对腿部生物力学的更集中理解，对腿部机器人的新启发，对自然底物的新理解，以及对跨学科科学家的培训。该项目由综合组织系统生物部的生理机制和生物力学计划、生物基础设施创新计划的生物部和工程局土木、机械和制造创新司的生物力学和机械生物学计划共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

This Faculty Early Career Development (CAREER) project combines biological experiments, mathematical modeling, and physical modeling to reveal the performance capabilities and constraints of legged locomotion in small invertebrates. When viewed on a relative scale, the fastest legged animals on the planet are the smallest of invertebrates. Organisms such as beetles, cockroaches, and mites are capable of running at speeds of tens to hundreds of body lengths per second. These remarkable feats of movement at the microscopic scale are enabled by strong limbs, robust foot attachment mechanics, and resilient exoskeleton structures that give these organisms locomotor capabilities vastly different from their larger counterparts. Yet smaller organisms also have to contend with incredibly complex and unstructured substrates that can impose step-to-step height variations equal to or larger than their leg length. This research will develop general principles of legged locomotion in complex environments which could contribute to the development of new legged robots that can move more effectively in unstructured environments. In parallel with the research aims, educational experiences for K-12, undergraduate, and academic professionals to better integrate living systems literacy into engineering curriculum will be developed. These activities include funded summer research experiences for underrepresented students in collaboration with a local Title 1 high school. At the college level, course development, hands-on training for undergraduate and graduate students, and interdisciplinary workshops for researchers in engineering and biology will be implemented. The overall goal of these efforts is to enable engagement, communication, and collaboration between engineers and biologists, facilitated through living systems literacy. This research project uses modeling and experiment to develop new geometric and dynamic scaling principles for legged locomotion in centimeter- and millimeter-scale organisms. Experiments will be performed with invertebrates that vary in size by four orders of magnitude in mass (the American cockroach, the Argentine ant, and the mite). To develop geometric scaling principles between animal morphology and natural substrates, a new experimental substrate-scanning platform to identify the three-dimensional topography of natural substrates will be developed. To study the dynamic scaling principles of force production and acceleration, new force measurement platforms to measure the ground-reaction forces involved in microscale legged locomotion will be developed. These experiments will be supported by physical modeling and computational modeling to elucidate scaling laws for dynamic and geometric phenomena in legged locomotion. The combination of experiments, modeling, and theory will improve our understanding of the biomechanics of microscale legged locomotion. The overall aim of this work is to contextualize the regimes of legged locomotion across the microscopic to macroscopic scales. The research and educational aims of this work are highly interdisciplinary. Graduate and high-school students will receive extensive training in biomechanics, physics, and engineering. Students will present results of these studies at robotics, physics, and biology conferences, and the outcomes will be published in interdisciplinary journals. Thus, the broader impacts include more focused understanding of legged biomechanics, new inspiration for legged robots, new understanding of natural substrates, and training of interdisciplinary scientists. This project was co-funded by the Physiological Mechanisms and Biomechanics Program in the BIO Division of Integrative Organismal Systems, the BIO Division of Biological Infrastructure Innovation Program, and the Biomechanics and Mechanobiology Program in the Engineering Directorate’s Civil, Mechanical, and Manufacturing Innovation Division.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.