ARRAYS OF MILLIMETER-SCALE RUBBER COMBUSTION ENGINES

The challenges associated with manufacturing power-dense, mm-scale, linear actuators are compounded when attempting to space large numbers of them closely together. When considering size, weight, power output and cost (SWaP-C) metrics, established actuation strategies tend to encounter steep mechanical performance barriers when engineered at the mm-scale, barriers which make one appreciate the elegance of skeletal muscle. A comparable mm-scale artificial muscle analog would be revolutionary, yet research has not replicated repeatable actuation structures close to the size of actin and myosin. There is now a growing commercial desire for arrays of 100s to 1000s of miniature actuators due to developments in the virtual reality and accessible technology industries. Rather than optimizing existing electrostatic, electromagnetic, piezoelectric, or thermal motion design principles, I investigate combustion’s potential to be a power-dense mm-scale actuation modality. With my colleagues, we find that oxygen-enriched mixtures of hydrocarbons, when ignited in molded rubber chambers, quickly inflate thin elastomeric “pistons” outward, producing kHz-frequency actuations with >1 W stroke power outputs. We confirm repeatable oxy-fuel combustion using mixtures containing methane, propane, and butane. In array configurations, microfluidic fuel delivery networks confine flames to their intended cylinder, enabling individual control of these closely spaced fluidic actuators without the need for valves. My soft end effector design provides a conformable, easily manufacturable actuation platform. Lessons from our microcombustion investigation are demonstrated in an untethered combustion system powering a 10x10 array of 2 mm-diameter bistable rubber dots, conceptually validating a potential wearable haptic or multiline tactile display technology.

Name thesis:degree_name

Ph. D., Theoretical and Applied Mechanics

Level thesis:degree_level

Doctor of Philosophy

Discipline thesis:degree_discipline

Theoretical and Applied Mechanics

Grantor

Cornell University

Year dc:date.issued

2023

Author dc:creator

• Heisser, Ronald

Committee members dc:contributor.committeemember

• Bouklas, Nikolaos
• Lal, Amit

• Microcombustion
• Microfluidics
• Soft robotics
• Tactile displays

Statement dc:rights

• Attribution 4.0 International

Licence dc:rights.uri

• https://creativecommons.org/licenses/by/4.0/

Language dc:language.iso

en

DOI

https://doi.org/10.7298/vvma-ma97

Dc Identifier Other

ProQuest Submission ID: 13785
ProQuest Publication ID: 30569852

OAI identifier oai:identifier

oai:ecommons.cornell.edu:1813/114648