{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,2]],"date-time":"2025-12-02T03:30:19Z","timestamp":1764646219588,"version":"build-2065373602"},"reference-count":34,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2019,9,6]],"date-time":"2019-09-06T00:00:00Z","timestamp":1567728000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003706","name":"Korea Research Institute of Standards and Science","doi-asserted-by":"publisher","award":["18011083"],"award-info":[{"award-number":["18011083"]}],"id":[{"id":"10.13039\/501100003706","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Basic Science Research Program through the National Research Foundation of Korea","award":["17442002"],"award-info":[{"award-number":["17442002"]}]},{"name":"Bio &amp; Medical Technology Development Program of the National Research Foundation (NRF)","award":["2018M3A9H6081482"],"award-info":[{"award-number":["2018M3A9H6081482"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Simultaneous measurement of skin physiological and physical properties are important for the diagnosis of skin diseases and monitoring of human performance, since it provides more comprehensive understanding on the skin conditions. Current skin analysis devices, however, require each of probes and unique protocols for the measurement of individual skin properties, resulting in inconvenience and increase of measurement uncertainty. This paper presents a pen-type skin analyzing device capable tomeasure three key skin properties at the same time: transepidermal water loss (TEWL), skin conductance, and skin hardness. It uses a single truncated hollow cone (THC) probe integrated with a humidity sensor, paired electrodes, and a load cell for the multimodal assessment of the skin properties. The present device measured TEWL with a sensitivity of 0.0068 (%\/s)\/(g\/m2\/h) and a linearity of 99.63%, conductance with a sensitivity of 1.02 \u00b5S\/\u00b5S and a linearity of 99.36%, and hardness with a sensitivity of 0.98 Shore 00\/Shore 00 and a linearity of 99.85%, within the appropriate ranges for the human skin. The present pen-type device has a high potential for the skin health diagnosis as well as the human performance monitoring applications.<\/jats:p>","DOI":"10.3390\/s19183857","type":"journal-article","created":{"date-parts":[[2019,9,9]],"date-time":"2019-09-09T03:14:41Z","timestamp":1567998881000},"page":"3857","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":19,"title":["Portable Skin Analyzers with Simultaneous Measurements of Transepidermal Water Loss, Skin Conductance and Skin Hardness"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3702-7245","authenticated-orcid":false,"given":"Daniel (Jai Kyoung)","family":"Sim","sequence":"first","affiliation":[{"name":"Center for Medical Convergence Metrology, Korea Research Institute of Standards and Science (KRISS), Daejeon 34113, Korea"},{"name":"711th Human Performance Wing, Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Dayton, OH 45433, USA"}]},{"given":"Sung Mok","family":"Kim","sequence":"additional","affiliation":[{"name":"Center for Medical Convergence Metrology, Korea Research Institute of Standards and Science (KRISS), Daejeon 34113, Korea"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9519-077X","authenticated-orcid":false,"given":"Steve S.","family":"Kim","sequence":"additional","affiliation":[{"name":"711th Human Performance Wing, Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Dayton, OH 45433, USA"}]},{"given":"Il","family":"Doh","sequence":"additional","affiliation":[{"name":"Center for Medical Convergence Metrology, Korea Research Institute of Standards and Science (KRISS), Daejeon 34113, Korea"},{"name":"Department of Medical Physics, University of Science and Technology (UST), Daejeon 34113, Korea"}]}],"member":"1968","published-online":{"date-parts":[[2019,9,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1100\/2012\/386936","article-title":"Variation of Biophysical Parameters of the Skin with Age, Gender, and Body Region","volume":"2012","author":"Firooz","year":"2012","journal-title":"Sci. World J."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1080\/09546630801958238","article-title":"Supplementation with Eskimo\u00ae Skin Care improves skin elasticity in women. A pilot study","volume":"19","author":"Segger","year":"2008","journal-title":"J. Dermatol. Treat."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1016\/j.ijpharm.2009.09.044","article-title":"The relationship between transepidermal water loss and skin permeability","volume":"384","author":"Machado","year":"2010","journal-title":"Int. J. Pharm."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1034\/j.1600-0846.2003.00025.x","article-title":"A closed unventilated chamber for the measurement of transepidermal water loss","volume":"9","author":"Nuutinen","year":"2003","journal-title":"Skin Res. Technol."},{"key":"ref_5","unstructured":"Berg, E.P., Pascut, F.C., Ciortea, L.I., Driscoll, D.O., Xiao, P., and Imhof, R.E. (2002, January 16\u201319). AquaFlux\u2014A New Instrument for Water Vapour Flux Density Measurement. Proceedings of the 4th international Symposium on Humidity & Moisture, Taipei, Taiwan."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1007\/BF00510358","article-title":"A Comparison of Techniques for the Measurement of Transepidermal Water Loss","volume":"274","author":"Oliver","year":"1982","journal-title":"Arch. Dermatol. Res."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"286","DOI":"10.1016\/j.clindermatol.2011.08.015","article-title":"Effect of moisturizers on epidermal barrier function","volume":"30","year":"2012","journal-title":"Clin. Dermatol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"550","DOI":"10.1111\/bjd.12134","article-title":"Assessment of skin barrier function in podoconiosis: Measurement of stratum corneum hydration and transepidermal water loss","volume":"168","author":"Ferguson","year":"2013","journal-title":"Br. J. Dermatol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1111\/j.1600-0846.1999.tb00126.x","article-title":"Comparative study of five instruments measuring stratum corneum hydration (Corneometer CM 820 and CM 825, Skicon 200, Nova DPM 9003, DermaLab). Part I. In vitro","volume":"5","author":"Fluhr","year":"1999","journal-title":"Skin Res. Technol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1016\/j.clindermatol.2011.08.007","article-title":"Structure and function of the epidermis related to barrier properties","volume":"30","author":"Baroni","year":"2012","journal-title":"Clin. Dermatol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1016\/j.snb.2016.04.137","article-title":"Portable sweat rate sensors integrated with air ventilation actuators","volume":"234","author":"Sim","year":"2016","journal-title":"Sens. Actuators B Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1181","DOI":"10.1038\/s41598-018-19239-8","article-title":"Wearable Sweat Rate Sensors for Human Thermal Comfort Monitoring","volume":"8","author":"Sim","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"787","DOI":"10.1111\/j.1469-8986.2007.00550.x","article-title":"Cardiovascular, electrodermal, and respiratory response patterns to fear- and sadness-inducing films","volume":"44","author":"Kreibig","year":"2007","journal-title":"Psychophysiology"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"23468","DOI":"10.1038\/srep23468","article-title":"A Flexible and Wearable Human Stress Monitoring Patch","volume":"6","author":"Yoon","year":"2016","journal-title":"Sci. Rep."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"188","DOI":"10.1016\/0190-9622(95)90124-8","article-title":"Use of a durometer to measure the degree of skin induration in lipodermatosclerosis","volume":"32","author":"Romanelli","year":"1995","journal-title":"J. Am. Acad. Dermatol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1016\/0190-9622(93)70150-R","article-title":"Use of a durometer to assess skin hardness","volume":"29","author":"Falanga","year":"1993","journal-title":"J. Am. Acad. Dermatol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"643","DOI":"10.1111\/j.1742-481X.2011.00932.x","article-title":"Quantification of the physical properties of keloid and hypertrophic scars using the Vesmeter novel sensing device","volume":"9","author":"Niyaz","year":"2012","journal-title":"Int. Wound J."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"308","DOI":"10.2340\/00015555-0080","article-title":"Mechanical properties and barrier function of healthy human skin","volume":"86","author":"Pedersen","year":"2006","journal-title":"Acta Derm. Venereol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1016\/j.jtv.2016.03.002","article-title":"Introduction to skin aging","volume":"26","author":"Tobin","year":"2017","journal-title":"J. Tissue Viability"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1016\/j.ajic.2006.05.295","article-title":"Structure and function of the epidermal barrier","volume":"34","author":"Wickett","year":"2006","journal-title":"Am. J. Infect. Control"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"12027","DOI":"10.1038\/s41598-018-30206-1","article-title":"Evaluation of Skin Hardness as a Physiological Sign of Human Thermal Status","volume":"8","author":"Yoon","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"253502","DOI":"10.1063\/1.4881888","article-title":"A flexible skin piloerection monitoring sensor","volume":"104","author":"Kim","year":"2014","journal-title":"Appl. Phys. Lett."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1002\/admt.201800628","article-title":"Multifunctional Skin-Inspired Flexible Sensor Systems for Wearable Electronics","volume":"4","author":"Xu","year":"2019","journal-title":"Adv. Mater. Technol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1700053","DOI":"10.1002\/admt.201700053","article-title":"Wearable Sensing Systems with Mechanically Soft Assemblies of Nanoscale Materials","volume":"2","author":"Lee","year":"2017","journal-title":"Adv. Mater. Technol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"9609","DOI":"10.1039\/C9TC01874C","article-title":"Highly stable kirigami-structured stretchable strain sensors for perdurable wearable electronics","volume":"7","author":"Xu","year":"2019","journal-title":"J. Mater. Chem. C"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1521","DOI":"10.1016\/j.burns.2014.01.025","article-title":"Reliability of scar assessments performed with an integrated skin testing device\u2014The DermaLab Combo\u00ae","volume":"40","author":"Gankande","year":"2014","journal-title":"Burns"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1111\/srt.12590","article-title":"Validation of GPSkin Barrier\u00ae for assessing epidermal permeability barrier function and stratum corneum hydration in humans","volume":"25","author":"Ye","year":"2019","journal-title":"Skin Res. Technol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2246","DOI":"10.1021\/acssensors.8b00272","article-title":"Truncated Hollow Cone Probe for Assessing Transepidermal Water Loss and Skin Hardness","volume":"3","author":"Sim","year":"2018","journal-title":"ACS Sens."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"6075","DOI":"10.3390\/s120506075","article-title":"A Stress Sensor Based on Galvanic Skin Response (GSR) Controlled by ZigBee","volume":"12","author":"Villarejo","year":"2012","journal-title":"Sensors"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1156","DOI":"10.1088\/0022-3727\/27\/6\/013","article-title":"The effect of indenter geometry on the elastic response to indentation","volume":"27","author":"Briscoe","year":"1994","journal-title":"J. Phys. D Appl. Phys."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1111\/j.1468-2494.2008.00476.x","article-title":"Closed-chamber transepidermal water loss measurement: Microclimate, calibration and performance","volume":"31","author":"Imhof","year":"2009","journal-title":"Int. J. Cosmet. Sci."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/j.sna.2005.04.001","article-title":"Transepidermal water loss sensor based on fast dew point hygrometer","volume":"123","author":"Jachowicz","year":"2005","journal-title":"Sens. Actuators A Phys."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Tarapata, G., Weremczuk, J., and Jachowicz, R. (2007, January 4\u20135). Evaluation of water barrier function of human skin using super fast dew point hygrometer. Proceedings of the International Workshop on Medical Measurements and Applications\u2014MeMeA 2007, Warsaw, Poland.","DOI":"10.1109\/MEMEA.2007.4285152"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"379","DOI":"10.1016\/j.nanoen.2017.04.013","article-title":"Direct-laser-patterned friction layer for the output enhancement of a triboelectric nanogenerator","volume":"35","author":"Kim","year":"2017","journal-title":"Nano Energy"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/18\/3857\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:17:35Z","timestamp":1760188655000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/18\/3857"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,9,6]]},"references-count":34,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2019,9]]}},"alternative-id":["s19183857"],"URL":"https:\/\/doi.org\/10.3390\/s19183857","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2019,9,6]]}}}