{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T22:04:08Z","timestamp":1777413848885,"version":"3.51.4"},"reference-count":32,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2024,8,30]],"date-time":"2024-08-30T00:00:00Z","timestamp":1724976000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Flexible ultrasonic devices represent a feasible technology for providing timely signal detection and even a non-invasive disease treatment for the human brain. However, the deformation of the devices is always accompanied by a change in the acoustic field, making it hard for accurate focusing. Herein, we report a stable and flexible transducer. This device can generate a high-intensity acoustic signal with a controllable acoustic field even when the device is bent. The key is to use a low-impedance piezoelectric material and an island-bridge device structure, as well as to design a unique time-reversal algorithm to correct the deviation of signals after transcranial propagation. To provide an in-depth study of the acoustic field of flexible devices, we also analyze the effects of mechanical deformation and structural parameters on the corresponding acoustic response.<\/jats:p>","DOI":"10.3390\/s24175635","type":"journal-article","created":{"date-parts":[[2024,8,30]],"date-time":"2024-08-30T07:45:47Z","timestamp":1725003947000},"page":"5635","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["A Unique Time-Reversal Algorithm-Enabled Flexible Ultrasound Transducer with a Controllable Acoustic Field"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8894-4908","authenticated-orcid":false,"given":"Lu","family":"Jia","sequence":"first","affiliation":[{"name":"Information Science Academy, China Electronics Technology Group Corporation, Beijing 100142, China"},{"name":"National Key Laboratory of Integrated Circuits and Microsystems, Beijing 100142, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yingzhan","family":"Yan","sequence":"additional","affiliation":[{"name":"Information Science Academy, China Electronics Technology Group Corporation, Beijing 100142, China"},{"name":"National Key Laboratory of Integrated Circuits and Microsystems, Beijing 100142, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jing","family":"Xu","sequence":"additional","affiliation":[{"name":"Information Science Academy, China Electronics Technology Group Corporation, Beijing 100142, China"},{"name":"National Key Laboratory of Integrated Circuits and Microsystems, Beijing 100142, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2997-9270","authenticated-orcid":false,"given":"Yuan","family":"Gao","sequence":"additional","affiliation":[{"name":"Information Science Academy, China Electronics Technology Group Corporation, Beijing 100142, China"},{"name":"National Key Laboratory of Integrated Circuits and Microsystems, Beijing 100142, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,8,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Zhang, X., Wang, C., Zheng, T., Wu, H., Wu, Q., and Wang, Y. (2023). Wearable Optical Fiber Sensors in Medical Monitoring Applications: A Review. Sensors, 23.","DOI":"10.3390\/s23156671"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"e2001496","DOI":"10.1002\/adma.202001496","article-title":"Water-Resistant Conformal Hybrid Electrodes for Aquatic Endurable Electrocardiographic Monitoring","volume":"32","author":"Ji","year":"2020","journal-title":"Adv. Mater."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2301138","DOI":"10.1002\/adem.202301138","article-title":"Skin-Mount Textile-Based Flexible Strain Sensors for Physiotherapy","volume":"2301138","author":"Javaid","year":"2024","journal-title":"Adv. Eng. Mater."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2101809","DOI":"10.1002\/aenm.202101809","article-title":"Realizing High-Energy and Stable Wire-Type Batteries with Flexible Lithium\u2014Metal Composite Yarns","volume":"11","author":"Gao","year":"2021","journal-title":"Adv. Energy Mater."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2203730","DOI":"10.1002\/adfm.202203730","article-title":"Inkjet-Printed Xerogel Scaffolds Enabled Room-Temperature Fabrication of High-Quality Metal Electrodes for Flexible Electronics","volume":"32","author":"Wang","year":"2022","journal-title":"Adv. Funct. Mater."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2305917","DOI":"10.1002\/adma.202305917","article-title":"Flexible and Stretchable Electrochemical Sensors for Biological Monitoring","volume":"2305917","author":"Zhao","year":"2023","journal-title":"Adv. Mater."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2002580","DOI":"10.1002\/aenm.202002580","article-title":"Fibrous Materials for Flexible Li\u2014S Battery","volume":"11","author":"Gao","year":"2020","journal-title":"Adv. Energy Mater."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"035101","DOI":"10.1088\/2631-7990\/acd827","article-title":"Electric-Driven Flexible-Roller Nanoimprint Lithography on the Stress-Sensitive Warped Wafer","volume":"5","author":"Fan","year":"2023","journal-title":"Int. J. Extrem. Manuf."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2002838","DOI":"10.1002\/aenm.202002838","article-title":"Textile Composite Electrodes for Flexible Batteries and Supercapacitors: Opportunities and Challenges","volume":"11","author":"Gao","year":"2021","journal-title":"Adv. Energy Mater."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"343re2","DOI":"10.1126\/scitranslmed.aaf6086","article-title":"Clinical Trial of Blood-Brain Barrier Disruption by Pulsed Ultrasound","volume":"8","author":"Carpentier","year":"2016","journal-title":"Sci. Transl. Med."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"eadf4888","DOI":"10.1126\/sciadv.adf4888","article-title":"BBB Opening with Focused Ultrasound in Nonhuman Primates and Parkinson\u2019s Disease Patients: Targeted AAV Vector Delivery and PET Imaging","volume":"9","author":"Blesa","year":"2023","journal-title":"Sci. Adv."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"850","DOI":"10.1038\/s41578-022-00427-y","article-title":"Soft Wearable Devices for Deep-Tissue Sensing","volume":"7","author":"Lin","year":"2022","journal-title":"Nat. Rev. Mater."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"687","DOI":"10.1038\/s41551-018-0287-x","article-title":"Monitoring of the Central Blood Pressure Waveform via a Conformal Ultrasonic Device","volume":"2","author":"Wang","year":"2018","journal-title":"Nat. Biomed. Eng."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"517","DOI":"10.1126\/science.abo2542","article-title":"Imaging of Diverse Organs","volume":"377","author":"Wang","year":"2022","journal-title":"Science"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"749","DOI":"10.1038\/s41551-021-00763-4","article-title":"Continuous Monitoring of Deep-Tissue Haemodynamics with Stretchable Ultrasonic Phased Arrays","volume":"5","author":"Wang","year":"2021","journal-title":"Nat. Biomed. Eng."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2321","DOI":"10.1007\/s00542-016-2912-5","article-title":"Flexible Piezoelectric Micromachined Ultrasonic Transducer (PMUT) for Application in Brain Stimulation","volume":"23","author":"Lee","year":"2017","journal-title":"Microsyst. Technol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"100096","DOI":"10.1016\/j.mne.2021.100096","article-title":"Design and Micromachining of a Stretchable Two-Dimensional Ultrasonic Array","volume":"13","author":"Liu","year":"2021","journal-title":"Micro Nano Eng."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3006","DOI":"10.1109\/TBME.2019.2899631","article-title":"Wearable Ultrasound Improves Motor Function in an MPTP Mouse Model of Parkinson\u2019s Disease","volume":"66","author":"Zhou","year":"2019","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"3375","DOI":"10.1109\/TBME.2021.3071807","article-title":"Transcranial Ultrasound Stimulation Suppresses Neuroinflammation in a Chronic Mouse Model of Parkinson\u2019s Disease","volume":"68","author":"Zhou","year":"2021","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"810","DOI":"10.1038\/s41586-024-07381-5","article-title":"Transcranial Volumetric Imaging Using a Conformal Ultrasound Patch","volume":"629","author":"Zhou","year":"2024","journal-title":"Nature"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Liu, W., and Wu, D. (2020). Low Temperature Adhesive Bonding-Based Fabrication of an Air-Borne Flexible Piezoelectric Micromachined Ultrasonic Transducer. Sensors, 20.","DOI":"10.3390\/s20113333"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"112476","DOI":"10.1016\/j.sna.2020.112476","article-title":"Flexible Piezoelectric Micro Ultrasonic Transducer Array Integrated on Various Flexible Substrates","volume":"317","author":"Liu","year":"2021","journal-title":"Sens. Actuators A Phys."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"24900","DOI":"10.1039\/c3ra44619k","article-title":"A Flexible Piezoelectric Micromachined Ultrasound Transducer","volume":"3","author":"Yang","year":"2013","journal-title":"RSC Adv."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2100785","DOI":"10.1002\/adhm.202100785","article-title":"Flexible Ultrasonic Patch for Accelerating Chronic Wound Healing","volume":"10","author":"Lyu","year":"2021","journal-title":"Adv. Healthc. Mater."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Powell, D.J., and Ward, G.H. (1991). A Performance Appraisal of Flexible Array Structures Using a Facet Ensemble Scattering Technique. Proc. IEEE Ultrason. Symp., 753\u2013756.","DOI":"10.1109\/ULTSYM.1991.234089"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Wang, Y.F., Ren, T.L., Yang, Y., Chen, H., Zhou, C.J., Wang, L.G., and Liu, L.T. (2011, January 23\u201327). High-Density PMUT Array for 3-D Ultrasonic Imaging Based on Reverse-Bonding Structure. Proceedings of the 2011 IEEE 24th International Conference on Micro Electro Mechanical Systems, Cancun, Mexico.","DOI":"10.1109\/MEMSYS.2011.5734605"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"eabi9283","DOI":"10.1126\/sciadv.abi9283","article-title":"Flexible Doppler Ultrasound Device for the Monitoring of Blood Flow Velocity","volume":"7","author":"Wang","year":"2021","journal-title":"Sci. Adv."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"eabg2507","DOI":"10.1126\/sciadv.abg2507","article-title":"A Flexible, Stretchable System for Simultaneous Acoustic Energy Transfer and Communication","volume":"7","author":"Jin","year":"2021","journal-title":"Sci. Adv."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"303","DOI":"10.1016\/j.jconrel.2020.05.020","article-title":"Focused Ultrasound for Opening Blood-Brain Barrier and Drug Delivery Monitored with Positron Emission Tomography","volume":"324","author":"Arif","year":"2020","journal-title":"J. Control. Release"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1207","DOI":"10.1118\/1.3531553","article-title":"Effects of Nonlinear Ultrasound Propagation on High Intensity Brain Therapy","volume":"38","author":"Pinton","year":"2011","journal-title":"Med. Phys."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1299\/jbse.7.43","article-title":"Focus Control in HIFU Therapy Assisted by Time-Reversal Simulation with an Iterative Procedure for Hot Spot Elimination","volume":"7","author":"Leduc","year":"2012","journal-title":"J. Biomech. Sci. Eng."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"3526","DOI":"10.1109\/TBME.2022.3173035","article-title":"Ultrasonic Methods for Brain Imaging: Techniques and Implications","volume":"69","author":"Zheng","year":"2022","journal-title":"IEEE Trans. Biomed. Eng."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/24\/17\/5635\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T15:45:41Z","timestamp":1760111141000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/24\/17\/5635"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,8,30]]},"references-count":32,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2024,9]]}},"alternative-id":["s24175635"],"URL":"https:\/\/doi.org\/10.3390\/s24175635","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,8,30]]}}}