{"id":{"repo_id":"cornell","oai_identifier":"oai:ecommons.cornell.edu:1813/120652"},"canonical_url":"https://search.dev.ndltd.org/etd/cornell/oai:ecommons.cornell.edu:1813/120652","repository":{"repo_id":"cornell","name":"Cornell University","base_url":"https://ecommons.cornell.edu/server/oai/request"},"display":{"title":"Designing a Wearable, Centimeter-Scale Generator Powered by Human Movement","abstract":"Wearable devices used in both research and industry require frequent recharg-ing. Typically, a device must be removed and charged separately, which reduces the device’s overall utility, especially if its primary function is for applications requiring continuous monitoring or actuation. To address this challenge, this work presents a compliant, centimeter-scale energy harvesting system that con- verts stored pneumatic energy via human movement into electricity intended to recharge a battery. The system design uses human footstrikes to pump air into an on-body pneumatic storage pouch. The released air then drives an axial flux induction generator, producing a maximum open circuit voltage of 3.89 Volts (V) and maintaining 2 V for over 38 seconds at a pouch pressure of 19.5 pounds per square inch absolute (psia). The generator’s design is guided by a mathe- matical model derived from Faraday’s Law along with magnetic field simula- tions in Ansys Maxwell. During the design process, emphasis was placed on wearability, form factor minimization, and fabrication using non-specialized, rapid-prototyping techniques. All structural components outside of the mag- nets, ball bearings, and center shaft are fabricated from compliant materials to enhance user comfort and device durability. The system is characterized across a range of pouch pressures and wall supply flowrates where a flowrate of 10 liters per minute (lpm) produced a maximum RMS output power of 34.7 milli- watts (mW) and a RMS voltage of 2.76 V. At this flowrate, the device outputs 12.6 milliamps (mA) which can trickle charge a 1.2 V nickel cadmium (NiCD) or nickel–metal hydride (NiMH) battery. While the generator’s pneumatic to electric power efficiency is approximately 0.73%, the current prototype’s out- put power, simplified fabrication techniques, and wearability demonstrate the feasibility of this system as a self-contained, human-powered, passive energy solution for low-power wearable electronics.","abstract_html":"Wearable devices used in both research and industry require frequent recharg-ing. Typically, a device must be removed and charged separately, which reduces the device’s overall utility, especially if its primary function is for applications requiring continuous monitoring or actuation. To address this challenge, this work presents a compliant, centimeter-scale energy harvesting system that con- verts stored pneumatic energy via human movement into electricity intended to recharge a battery. The system design uses human footstrikes to pump air into an on-body pneumatic storage pouch. The released air then drives an axial flux induction generator, producing a maximum open circuit voltage of 3.89 Volts (V) and maintaining 2 V for over 38 seconds at a pouch pressure of 19.5 pounds per square inch absolute (psia). The generator’s design is guided by a mathe- matical model derived from Faraday’s Law along with magnetic field simula- tions in Ansys Maxwell. During the design process, emphasis was placed on wearability, form factor minimization, and fabrication using non-specialized, rapid-prototyping techniques. All structural components outside of the mag- nets, ball bearings, and center shaft are fabricated from compliant materials to enhance user comfort and device durability. The system is characterized across a range of pouch pressures and wall supply flowrates where a flowrate of 10 liters per minute (lpm) produced a maximum RMS output power of 34.7 milli- watts (mW) and a RMS voltage of 2.76 V. At this flowrate, the device outputs 12.6 milliamps (mA) which can trickle charge a 1.2 V nickel cadmium (NiCD) or nickel–metal hydride (NiMH) battery. While the generator’s pneumatic to electric power efficiency is approximately 0.73%, the current prototype’s out- put power, simplified fabrication techniques, and wearability demonstrate the feasibility of this system as a self-contained, human-powered, passive energy solution for low-power wearable electronics.","abstract_has_math":false,"creators":["Simmons, Devin"],"institution":"Cornell University","degree_name":"M.S., Mechanical Engineering","degree_level":"Master of Science","degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":["Helbling, Elizabeth"],"year":2025,"date_issued":"2025-08","date_published":"2025-08","updated_at":"2026-07-24T01:49:04Z","subjects":[],"languages":["en"],"rights":["Attribution 4.0 International"],"rights_urls":["https://creativecommons.org/licenses/by/4.0/"],"identifier_entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.7298/ttkp-9p04"],"render_values":[{"text":"https://doi.org/10.7298/ttkp-9p04","href":"https://doi.org/10.7298/ttkp-9p04","code":true}]},{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["ProQuest Submission ID: 12578","ProQuest Publication ID: 32171204"],"render_values":[{"text":"ProQuest Submission ID: 12578","href":null,"code":true},{"text":"ProQuest Publication ID: 32171204","href":null,"code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/1813/120652","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Helbling, Elizabeth"]},{"key":"dc:creator","label":"Author","values":["Simmons, Devin"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2026-04-02T18:33:34Z"]},{"key":"dc:date.issued","label":"Date","values":["2025-08"]},{"key":"dc:type","label":"Dc Type","values":["dissertation or thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Master of Science"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S., Mechanical Engineering"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Cornell University"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Attribution 4.0 International"]},{"key":"dc:rights.uri","label":"Rights URI","values":["https://creativecommons.org/licenses/by/4.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.7298/ttkp-9p04"]},{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["ProQuest Submission ID: 12578","ProQuest Publication ID: 32171204"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/1813/120652"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["100 pages"]},{"key":"dc:description.abstract","label":"Abstract","values":["Wearable devices used in both research and industry require frequent recharg-ing. Typically, a device must be removed and charged separately, which reduces the device’s overall utility, especially if its primary function is for applications requiring continuous monitoring or actuation. To address this challenge, this work presents a compliant, centimeter-scale energy harvesting system that con- verts stored pneumatic energy via human movement into electricity intended to recharge a battery. The system design uses human footstrikes to pump air into an on-body pneumatic storage pouch. The released air then drives an axial flux induction generator, producing a maximum open circuit voltage of 3.89 Volts (V) and maintaining 2 V for over 38 seconds at a pouch pressure of 19.5 pounds per square inch absolute (psia). The generator’s design is guided by a mathe- matical model derived from Faraday’s Law along with magnetic field simula- tions in Ansys Maxwell. During the design process, emphasis was placed on wearability, form factor minimization, and fabrication using non-specialized, rapid-prototyping techniques. All structural components outside of the mag- nets, ball bearings, and center shaft are fabricated from compliant materials to enhance user comfort and device durability. The system is characterized across a range of pouch pressures and wall supply flowrates where a flowrate of 10 liters per minute (lpm) produced a maximum RMS output power of 34.7 milli- watts (mW) and a RMS voltage of 2.76 V. At this flowrate, the device outputs 12.6 milliamps (mA) which can trickle charge a 1.2 V nickel cadmium (NiCD) or nickel–metal hydride (NiMH) battery. While the generator’s pneumatic to electric power efficiency is approximately 0.73%, the current prototype’s out- put power, simplified fabrication techniques, and wearability demonstrate the feasibility of this system as a self-contained, human-powered, passive energy solution for low-power wearable electronics."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Designing a Wearable, Centimeter-Scale Generator Powered by Human Movement"]}]}],"canonical_facts":{"dc:contributor.committeemember":["Helbling, Elizabeth"],"dc:creator":["Simmons, Devin"],"dc:date.accessioned":["2026-04-02T18:33:34Z"],"dc:date.issued":["2025-08"],"dc:description":["100 pages"],"dc:description.abstract":["Wearable devices used in both research and industry require frequent recharg-ing. Typically, a device must be removed and charged separately, which reduces the device’s overall utility, especially if its primary function is for applications requiring continuous monitoring or actuation. To address this challenge, this work presents a compliant, centimeter-scale energy harvesting system that con- verts stored pneumatic energy via human movement into electricity intended to recharge a battery. The system design uses human footstrikes to pump air into an on-body pneumatic storage pouch. The released air then drives an axial flux induction generator, producing a maximum open circuit voltage of 3.89 Volts (V) and maintaining 2 V for over 38 seconds at a pouch pressure of 19.5 pounds per square inch absolute (psia). The generator’s design is guided by a mathe- matical model derived from Faraday’s Law along with magnetic field simula- tions in Ansys Maxwell. During the design process, emphasis was placed on wearability, form factor minimization, and fabrication using non-specialized, rapid-prototyping techniques. All structural components outside of the mag- nets, ball bearings, and center shaft are fabricated from compliant materials to enhance user comfort and device durability. The system is characterized across a range of pouch pressures and wall supply flowrates where a flowrate of 10 liters per minute (lpm) produced a maximum RMS output power of 34.7 milli- watts (mW) and a RMS voltage of 2.76 V. At this flowrate, the device outputs 12.6 milliamps (mA) which can trickle charge a 1.2 V nickel cadmium (NiCD) or nickel–metal hydride (NiMH) battery. While the generator’s pneumatic to electric power efficiency is approximately 0.73%, the current prototype’s out- put power, simplified fabrication techniques, and wearability demonstrate the feasibility of this system as a self-contained, human-powered, passive energy solution for low-power wearable electronics."],"dc:format.mimetype":["application/pdf"],"dc:identifier.doi":["https://doi.org/10.7298/ttkp-9p04"],"dc:identifier.other":["ProQuest Submission ID: 12578","ProQuest Publication ID: 32171204"],"dc:identifier.uri":["https://hdl.handle.net/1813/120652"],"dc:language.iso":["en"],"dc:rights":["Attribution 4.0 International"],"dc:rights.uri":["https://creativecommons.org/licenses/by/4.0/"],"dc:title":["Designing a Wearable, Centimeter-Scale Generator Powered by Human Movement"],"dc:type":["dissertation or thesis"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_level":["Master of Science"],"thesis:degree_name":["M.S., Mechanical Engineering"],"thesis:institution_name":["Cornell University"]},"updated_at":"2026-07-24T01:49:04Z"}