{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/119401"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/119401","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Design and Development of Single Element Focused Ultrasound Transducers","abstract":"Histotripsy is a non-invasive, non-thermal, and non-ionizing therapy that utilizes converging high-pressure ultrasound waves at a focal point to produce cavitation and induce mechanical tissue destruction. Currently, rapid prototyped histotripsy transducers consist of multiple elements and are made using 3D printing methods. Multi-element transducers introduce size constraints and 3D printing has limitations in material choice, cost, and time for larger scale manufacturing. This thesis investigates the development of rapid prototyped single element histotripsy transducers and the use of injection molding for transducer fabrication, utilizing an in-house metal CNC mill for mold manufacturing and a desktop injection molding machine. Nylon 101 and 30% glass-filled nylon were chosen as the plastics to inject as these were found to have the most similar acoustic properties to WaterShed, an ABS-like plastic currently used. Six single-element transducers were constructed with a 2 MHz curved Pz26 piezoceramic disc: two with SLA 3D printed housing, two with SLS 3D printed housing, and two with injection molded housing. Electrical impedance, beam dimensions, focal pressure output, and cavitation were characterized for each element. The results show that rapid prototyped single element transducers can generate enough pressure to perform histotripsy. This marks the development of the first rapid prototyped single element histotripsy transducer and further confirms that injection molding can produce transducers comparable, if not identical or potentially superior, to 3D printed counterparts. Future work aims to further characterize these transducers, explore more material options, and apply injection molding to various transducer designs while optimizing both CNC and injection molding parameters.","abstract_html":"Histotripsy is a non-invasive, non-thermal, and non-ionizing therapy that utilizes converging high-pressure ultrasound waves at a focal point to produce cavitation and induce mechanical tissue destruction. Currently, rapid prototyped histotripsy transducers consist of multiple elements and are made using 3D printing methods. Multi-element transducers introduce size constraints and 3D printing has limitations in material choice, cost, and time for larger scale manufacturing. This thesis investigates the development of rapid prototyped single element histotripsy transducers and the use of injection molding for transducer fabrication, utilizing an in-house metal CNC mill for mold manufacturing and a desktop injection molding machine. Nylon 101 and 30% glass-filled nylon were chosen as the plastics to inject as these were found to have the most similar acoustic properties to WaterShed, an ABS-like plastic currently used. Six single-element transducers were constructed with a 2 MHz curved Pz26 piezoceramic disc: two with SLA 3D printed housing, two with SLS 3D printed housing, and two with injection molded housing. Electrical impedance, beam dimensions, focal pressure output, and cavitation were characterized for each element. The results show that rapid prototyped single element transducers can generate enough pressure to perform histotripsy. This marks the development of the first rapid prototyped single element histotripsy transducer and further confirms that injection molding can produce transducers comparable, if not identical or potentially superior, to 3D printed counterparts. Future work aims to further characterize these transducers, explore more material options, and apply injection molding to various transducer designs while optimizing both CNC and injection molding parameters.","abstract_has_math":false,"creators":["Dodoo, Neffisah Fadillah Naa Darkua"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Biomedical Engineering","degree_department":"Department of Biomedical Engineering and Mechanics","school":null,"contributors":[],"advisors":[],"committee_chairs":["Vlaisavljevich, Eli"],"committee_members":["Maxwell, Adam","Shahab, Shima"],"year":2024,"date_issued":"2024-06-11","date_published":"2024-06-11","updated_at":"2026-07-22T22:20:03Z","subjects":["focused ultrasound","histotripsy","prototyping","3D printing","injection molding","transducer"],"languages":["en"],"rights":["Creative Commons Attribution-ShareAlike 4.0 International"],"rights_urls":["http://creativecommons.org/licenses/by-sa/4.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:40712"],"render_values":[{"text":"vt_gsexam:40712","href":null,"code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/10919/119401","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Vlaisavljevich, Eli"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Maxwell, Adam","Shahab, Shima"]},{"key":"dc:contributor.department","label":"Department","values":["Department of Biomedical Engineering and Mechanics"]},{"key":"dc:creator","label":"Author","values":["Dodoo, Neffisah Fadillah Naa Darkua"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2024-06-12T08:01:28Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2024-06-12T08:01:28Z"]},{"key":"dc:date.issued","label":"Date","values":["2024-06-11"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biomedical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["focused ultrasound","histotripsy","prototyping","3D printing","injection molding","transducer"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Creative Commons Attribution-ShareAlike 4.0 International"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://creativecommons.org/licenses/by-sa/4.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:40712"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10919/119401"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Histotripsy is a non-invasive, non-thermal, and non-ionizing therapy that utilizes converging high-pressure ultrasound waves at a focal point to produce cavitation and induce mechanical tissue destruction. Currently, rapid prototyped histotripsy transducers consist of multiple elements and are made using 3D printing methods. Multi-element transducers introduce size constraints and 3D printing has limitations in material choice, cost, and time for larger scale manufacturing. This thesis investigates the development of rapid prototyped single element histotripsy transducers and the use of injection molding for transducer fabrication, utilizing an in-house metal CNC mill for mold manufacturing and a desktop injection molding machine. Nylon 101 and 30% glass-filled nylon were chosen as the plastics to inject as these were found to have the most similar acoustic properties to WaterShed, an ABS-like plastic currently used. Six single-element transducers were constructed with a 2 MHz curved Pz26 piezoceramic disc: two with SLA 3D printed housing, two with SLS 3D printed housing, and two with injection molded housing. Electrical impedance, beam dimensions, focal pressure output, and cavitation were characterized for each element. The results show that rapid prototyped single element transducers can generate enough pressure to perform histotripsy. This marks the development of the first rapid prototyped single element histotripsy transducer and further confirms that injection molding can produce transducers comparable, if not identical or potentially superior, to 3D printed counterparts. Future work aims to further characterize these transducers, explore more material options, and apply injection molding to various transducer designs while optimizing both CNC and injection molding parameters."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["Histotripsy is a form of cancer therapy that can non-invasively treat tumors using focused ultrasound waves. Focused ultrasound transducers are used to achieve this and are currently prototyped using 3D printing. However, these methods are limiting in material options and upscale manufacturing. Many of these devices currently used tend to be larger in size, comparable to the size of a mixing bowl, which limits its applications. This thesis investigates the development of single element histotripsy transducers and the use of injection molding for transducer fabrication, using an in-house metal CNC mill for mold manufacturing and desktop injection molding machine. Nylon 101 and 30% glass-filled nylon were chosen as the plastics to inject due to their ideal acoustic properties. Six single-element transducers were constructed: two with SLA 3D printing, two with SLS 3D printing, and two with injection molding. All transducers were tested and compared against each other. The results show that 3D printed single element transducers can perform histotripsy and that injection molding can produce comparable results. Future work should continue to test and characterize these transducers, explore more material options for injection molding, apply injection molding to other transducer designs, and optimize CNC and injection molding parameters."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Design and Development of Single Element Focused Ultrasound Transducers"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Vlaisavljevich, Eli"],"dc:contributor.committeemember":["Maxwell, Adam","Shahab, Shima"],"dc:contributor.department":["Department of Biomedical Engineering and Mechanics"],"dc:creator":["Dodoo, Neffisah Fadillah Naa Darkua"],"dc:date.accessioned":["2024-06-12T08:01:28Z"],"dc:date.available":["2024-06-12T08:01:28Z"],"dc:date.issued":["2024-06-11"],"dc:description.abstract":["Histotripsy is a non-invasive, non-thermal, and non-ionizing therapy that utilizes converging high-pressure ultrasound waves at a focal point to produce cavitation and induce mechanical tissue destruction. Currently, rapid prototyped histotripsy transducers consist of multiple elements and are made using 3D printing methods. Multi-element transducers introduce size constraints and 3D printing has limitations in material choice, cost, and time for larger scale manufacturing. This thesis investigates the development of rapid prototyped single element histotripsy transducers and the use of injection molding for transducer fabrication, utilizing an in-house metal CNC mill for mold manufacturing and a desktop injection molding machine. Nylon 101 and 30% glass-filled nylon were chosen as the plastics to inject as these were found to have the most similar acoustic properties to WaterShed, an ABS-like plastic currently used. Six single-element transducers were constructed with a 2 MHz curved Pz26 piezoceramic disc: two with SLA 3D printed housing, two with SLS 3D printed housing, and two with injection molded housing. Electrical impedance, beam dimensions, focal pressure output, and cavitation were characterized for each element. The results show that rapid prototyped single element transducers can generate enough pressure to perform histotripsy. This marks the development of the first rapid prototyped single element histotripsy transducer and further confirms that injection molding can produce transducers comparable, if not identical or potentially superior, to 3D printed counterparts. Future work aims to further characterize these transducers, explore more material options, and apply injection molding to various transducer designs while optimizing both CNC and injection molding parameters."],"dc:description.abstractgeneral":["Histotripsy is a form of cancer therapy that can non-invasively treat tumors using focused ultrasound waves. Focused ultrasound transducers are used to achieve this and are currently prototyped using 3D printing. However, these methods are limiting in material options and upscale manufacturing. Many of these devices currently used tend to be larger in size, comparable to the size of a mixing bowl, which limits its applications. This thesis investigates the development of single element histotripsy transducers and the use of injection molding for transducer fabrication, using an in-house metal CNC mill for mold manufacturing and desktop injection molding machine. Nylon 101 and 30% glass-filled nylon were chosen as the plastics to inject due to their ideal acoustic properties. Six single-element transducers were constructed: two with SLA 3D printing, two with SLS 3D printing, and two with injection molding. All transducers were tested and compared against each other. The results show that 3D printed single element transducers can perform histotripsy and that injection molding can produce comparable results. Future work should continue to test and characterize these transducers, explore more material options for injection molding, apply injection molding to other transducer designs, and optimize CNC and injection molding parameters."],"dc:description.degree":["Master of Science"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:40712"],"dc:identifier.uri":["https://hdl.handle.net/10919/119401"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["Creative Commons Attribution-ShareAlike 4.0 International"],"dc:rights.uri":["http://creativecommons.org/licenses/by-sa/4.0/"],"dc:subject":["focused ultrasound","histotripsy","prototyping","3D printing","injection molding","transducer"],"dc:title":["Design and Development of Single Element Focused Ultrasound Transducers"],"dc:type":["Thesis"],"thesis:degree_discipline":["Biomedical Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:03Z"}