{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,9]],"date-time":"2026-03-09T15:45:23Z","timestamp":1773071123711,"version":"3.50.1"},"reference-count":17,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2022,7,15]],"date-time":"2022-07-15T00:00:00Z","timestamp":1657843200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000646","name":"Japan Society for the Promotion of Science KAKENHI","doi-asserted-by":"publisher","award":["JP20H02121"],"award-info":[{"award-number":["JP20H02121"]}],"id":[{"id":"10.13039\/501100000646","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000646","name":"Japan Society for the Promotion of Science KAKENHI","doi-asserted-by":"publisher","award":["JPMJCR19A2"],"award-info":[{"award-number":["JPMJCR19A2"]}],"id":[{"id":"10.13039\/501100000646","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002241","name":"Japan Science and Technology Agency CREST","doi-asserted-by":"publisher","award":["JP20H02121"],"award-info":[{"award-number":["JP20H02121"]}],"id":[{"id":"10.13039\/501100002241","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002241","name":"Japan Science and Technology Agency CREST","doi-asserted-by":"publisher","award":["JPMJCR19A2"],"award-info":[{"award-number":["JPMJCR19A2"]}],"id":[{"id":"10.13039\/501100002241","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Deducing the input signal for a tactile display to present the target surface (i.e., solving the inverse problem for tactile displays) is challenging. We proposed the encoding and presentation (EP) method in our prior work, where we encoded the target surface by scanning it using an array of piezoelectric devices (encoding) and then drove the piezoelectric devices using the obtained signals to display the surface (presentation). The EP method reproduced the target texture with an accuracy of over 80% for the five samples tested, which we refer to as replicability. Machine learning is a promising method for solving inverse problems. In this study, we designed a neural network to connect the subjective evaluation of tactile sensation and the input signals to a display; these signals are described as time-domain waveforms. First, participants were asked to touch the surface presented by the mechano-tactile display based on the encoded data from the EP method. Then, the participants recorded the similarity of the surface compared to five material samples, which were used as the input. The encoded data for the material samples were used as the output to create a dataset of 500 vectors. By training a multilayer perceptron with the dataset, we deduced new inputs for the display. The results indicate that using machine learning for fine tuning leads to significantly better accuracy in deducing the input compared to that achieved using the EP method alone. The proposed method is therefore considered a good solution for the inverse problem for tactile displays.<\/jats:p>","DOI":"10.3390\/s22145299","type":"journal-article","created":{"date-parts":[[2022,7,18]],"date-time":"2022-07-18T01:53:22Z","timestamp":1658109202000},"page":"5299","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Machine-Learning-Based Fine Tuning of Input Signals for Mechano-Tactile Display"],"prefix":"10.3390","volume":"22","author":[{"given":"Shuto","family":"Yamanaka","sequence":"first","affiliation":[{"name":"Department of Mechanical Engineering, Keio University, Yokohama 223-8522, Kanagawa, Japan"}]},{"given":"Tatsuho","family":"Nagatomo","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Keio University, Yokohama 223-8522, Kanagawa, Japan"}]},{"given":"Takefumi","family":"Hiraki","sequence":"additional","affiliation":[{"name":"Faculty of Library, Information and Media Science, University of Tsukuba, Tsukuba 305-8550, Ibaragi, Japan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9920-6903","authenticated-orcid":false,"given":"Hiroki","family":"Ishizuka","sequence":"additional","affiliation":[{"name":"Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Osaka, Japan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5632-2143","authenticated-orcid":false,"given":"Norihisa","family":"Miki","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Keio University, Yokohama 223-8522, Kanagawa, Japan"}]}],"member":"1968","published-online":{"date-parts":[[2022,7,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1016\/j.displa.2007.07.003","article-title":"Tactile displays: Overview and recent advances","volume":"29","author":"Chouvardas","year":"2008","journal-title":"Displays"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1016\/j.displa.2014.10.007","article-title":"Mems-based tactile displays","volume":"37","author":"Ishizuka","year":"2015","journal-title":"Displays"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"580","DOI":"10.1109\/TOH.2017.2689006","article-title":"Wearable haptic systems for the fingertip and the hand: Taxonomy, review, and perspectives","volume":"10","author":"Pacchierotti","year":"2017","journal-title":"IEEE Trans. Haptics"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1109\/TOH.2020.3018754","article-title":"A survey of mid-air ultrasound haptics and its applications","volume":"14","author":"Rakkolainen","year":"2020","journal-title":"IEEE Trans. Haptics"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"132","DOI":"10.1145\/1060581.1060587","article-title":"Display of virtual braille dots by lateral skin deformation: Feasibility study","volume":"2","author":"Levesque","year":"2005","journal-title":"ACM Trans. Appl. Percept."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Zhao, F., Fukuyama, K., and Sawada, H. (2009, January 27). Compact braille display using SMA wire array. Proceedings of the 18th IEEE International Symposium on Robot and Human Interactive Communication, Toyama, Japan.","DOI":"10.1109\/ROMAN.2009.5326301"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1109\/TOH.2019.2912960","article-title":"Wearable tactile display based on thermal expansion of nichrome wire","volume":"12","author":"Kajimoto","year":"2019","journal-title":"IEEE Trans. Haptics"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"94","DOI":"10.1299\/jsmec.41.94","article-title":"Relationship between the structure of human finger tissue and the location of tactile receptors","volume":"41","author":"Maeno","year":"1998","journal-title":"JSME Int. J. Ser. C Mech. Syst."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1016\/j.sna.2009.07.002","article-title":"MEMS-based hydraulic displacement amplification mechanism with completely encapsulated liquid","volume":"166","author":"Ninomiya","year":"2011","journal-title":"Sens. Actuat. A Phys."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"06JM11","DOI":"10.7567\/JJAP.53.06JM11","article-title":"Characterization of surfaces virtually created using MEMS tactile display","volume":"53","author":"Kosemura","year":"2014","journal-title":"Jap. J. Appl. Phys."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1016\/j.sna.2017.03.035","article-title":"Encoding and presentation of surface textures using a mechanotactile display","volume":"261","author":"Kawazoe","year":"2017","journal-title":"Sens. Actuat. A Phys."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"298","DOI":"10.1109\/TOH.2019.2932990","article-title":"Data-driven texture modeling and rendering on electrovibration display","volume":"13","author":"Osgouei","year":"2020","journal-title":"IEEE Trans. Haptics"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Lin, Z., and Smith, S. (2017, January 26). A natural user interface for realistic tactile perception of object surface texture. Proceedings of the 9th International Conference on Intelligent Human-Machine Systems and Cybernetics, Hangzhou, China.","DOI":"10.1109\/IHMSC.2017.194"},{"key":"ref_14","unstructured":"Cai, S., Ban, Y., Narumi, T., and Zhu, K. (2020, January 2). FrictGAN: Frictional signal generation from fabric texture images using generative adversarial network. Proceedings of the 30th International Conference on Artificial Reality and Telexistence and the 25th Eurographics Symposium on Virtual Environments, Virtual Event."},{"key":"ref_15","unstructured":"Kingma, D.P., and Ba, J. (2015, January 7). Adam: A method for stochastic optimization. Proceedings of the 3rd International Conference on Learning Representations, San Diego, CA, USA."},{"key":"ref_16","unstructured":"Reddi, S.J., Kale, S., and Kumar, S. (2018, January 30). On the convergence of adam and beyond. Proceedings of the 6th International Conference on Learning Representations, Vancouver, BC, Canada."},{"key":"ref_17","unstructured":"Nagatomo, T., Hiraki, T., Ishizuka, H., and Miki, N. (2021). Unsupervised learning enables extraction of tactile information from text database. IEEE Access, early access."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/14\/5299\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:51:25Z","timestamp":1760140285000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/14\/5299"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,7,15]]},"references-count":17,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2022,7]]}},"alternative-id":["s22145299"],"URL":"https:\/\/doi.org\/10.3390\/s22145299","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,7,15]]}}}