Biological Actuators: biologic sensing, processing, and control for soft robots
Abstract
Biological creatures leverage a complex hierarchical motor control system to navigate unpredictable environments with adaptability, dexterity, and efficiency that outperform abiotic actuators. Leveraging biological actuators in engineered machines, such as locomotive soft robots, could yield robots that display complex functional behaviors that have yet to be replicated in human-made systems, such as exercise-mediated strengthening and damage-triggered healing.1 Using biological materials to advance the capabilities of ÒbiohybridÓ robots could significantly expand their real-world impact in defense applications. One potential application of relevance to the army is in untethered exploratory robots. We envision a biohybrid robot that can detect a biochemical toxin in the environment, move towards it, deliver a payload to neutralize the toxin, and self-destruct. This would enable detecting and terminating biological and chemical threats without risking the lives of army personnel. Accomplishing this goal will require a series of technical advances that are described in this proposal. The biological motor control system consists of an upstream control center (motor cortex in the brain) that integrate various environmental signals into a decision to initiate or suppress movement. They relay this signal to motor neurons in the spinal cord, which are able to selectively activate specific sets of skeletal muscle fibers to modulate the amount and location of generated force. We have previously developed engineered muscle as an actuator to power locomotion of soft robots. However, upstream signaling in the form of motor neurons and cortical neurons have yet to be integrated with these engineered muscles. This is largely because of a lack of tools to measure and control the intercellular biochemical signaling that guides hierarchical organization in the neuromuscular system. This proposal outlines an approach to engineering muscle in which light-guided biochemical patterning in 4D drives innervation by motor neurons (Task 1). The ability to guide muscle innervation will drive the bottoms-up assembly of multiple motor units that can be controlled separately or together to modulate force output and power locomotion (Task 2). Integrating cortical neurons upstream of motor neurons will enable autonomously synthesizing and processing a range of environmental cues into directional locomotion (Task 3). Successful completion of Tasks 1-3 will result in the first biohybrid robot capable of autonomous self-directed locomotion without human intervention or navigational guidance. Scaling biological actuators from the mesoscale (mm) to the macroscale (cm+) to maximize force output will require developing a 3D bio-printing apparatus to manufacture complex multicellular architectures incorporating vascular networks (Task 4). This apparatus will also enable patterning micro-environmental niches within engineered tissues that can house satellite stem cells and drive self-healing in response to damage (Task 5). It can also be used to manufacture actuators containing on-board triggerable Òkill switchesÓ and provide dynamic control over robot lifetime (Task 6). Successful completion of Tasks 4-6 will result in the first biohybrid robot that is vascularized, can self-heal, and can self-destruct on demand. Our goal is to establish the fundamental technologies that enable fabricating adaptive soft robots which leverage biological motor control. This proposal will set the stage for the next generation of autonomous machines that adapt to dynamic environments and are poised to address real-world challenges of relevance to the army, including untethered exploratory robots.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 02, 2022
- Source ID
- W911NF2210126
Entities
People
- Ritu Raman
Organizations
- Army Contracting Command
- Massachusetts Institute of Technology
- United States Army