{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,13]],"date-time":"2026-05-13T09:20:15Z","timestamp":1778664015868,"version":"3.51.4"},"reference-count":43,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2022,7,8]],"date-time":"2022-07-08T00:00:00Z","timestamp":1657238400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"BULGARIAN NATIONAL SCIENCE FUND at the Ministry of Education and Science, Bulgaria","award":["KP-06-H27\/11"],"award-info":[{"award-number":["KP-06-H27\/11"]}]},{"name":"11 December 2018 \u201cAntenna technology for wearable devices in the future communication networks\u201d","award":["KP-06-H27\/11"],"award-info":[{"award-number":["KP-06-H27\/11"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In recent years, there has been a rapid development in the wearable industry. The growing number of wearables has led to the demand for new lightweight, flexible wearable antennas. In order to be applicable in IoT wearable devices, the antennas must meet certain electrical, mechanical, manufacturing, and safety requirements (e.g., specific absorption rate (SAR) below worldwide limits). However, the assessment of SAR does not provide information on the mechanisms of interaction between low-intensity electromagnetic fields emitted by wearable antennas and the human body. In this paper, we presented a detailed investigation of the SAR induced in erythrocyte suspensions from a fully textile wearable antenna at realistic (net input power 6.3 mW) and conservative (net input power 450 mW) conditions at 2.41 GHz, as well as results from in vitro experiments on the stability of human erythrocyte membranes at both exposure conditions. The detailed investigation showed that the 1 g average SARs were 0.5758 W\/kg and 41.13 W\/kg, respectively. Results from the in vitro experiments demonstrated that the short-term (20 min) irradiation of erythrocyte membranes in the reactive near-field of the wearable antenna at 6.3 mW input power had a stabilizing effect. Long-term exposure (120 min) had a destabilizing effect on the erythrocyte membrane.<\/jats:p>","DOI":"10.3390\/s22145139","type":"journal-article","created":{"date-parts":[[2022,7,11]],"date-time":"2022-07-11T00:06:21Z","timestamp":1657497981000},"page":"5139","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Wearable Antennas for Sensor Networks and IoT Applications: Evaluation of SAR and Biological Effects"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7707-0133","authenticated-orcid":false,"given":"Nikolay Todorov","family":"Atanasov","sequence":"first","affiliation":[{"name":"Department of Communication and Computer Engineering, South-West University \u201cNeofit Rilski\u201d, 2700 Blagoevgrad, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7177-8317","authenticated-orcid":false,"given":"Gabriela Lachezarova","family":"Atanasova","sequence":"additional","affiliation":[{"name":"Department of Communication and Computer Engineering, South-West University \u201cNeofit Rilski\u201d, 2700 Blagoevgrad, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Boyana","family":"Angelova","sequence":"additional","affiliation":[{"name":"Department of Biophysics and Radiobiology, Sofia University \u201cSt. Kliment Ohridski\u201d, 1164 Sofia, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Momchil","family":"Paunov","sequence":"additional","affiliation":[{"name":"Department of Biophysics and Radiobiology, Sofia University \u201cSt. Kliment Ohridski\u201d, 1164 Sofia, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maria","family":"Gurmanova","sequence":"additional","affiliation":[{"name":"Department of Biophysics and Radiobiology, Sofia University \u201cSt. Kliment Ohridski\u201d, 1164 Sofia, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1914-6160","authenticated-orcid":false,"given":"Margarita","family":"Kouzmanova","sequence":"additional","affiliation":[{"name":"Department of Biophysics and Radiobiology, Sofia University \u201cSt. Kliment Ohridski\u201d, 1164 Sofia, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,7,8]]},"reference":[{"key":"ref_1","unstructured":"(2022, February 14). Statista. Available online: https:\/\/www.statista.com\/statistics\/487291\/global-connected-wearable-devices\/."},{"key":"ref_2","first-page":"143","article-title":"Wearable Textile Antennas with High Body-Area Isolation: Design, Fabrication, and Characterization Aspects","volume":"Volume 1","year":"2020","journal-title":"Modern Printed Circuit Antennas"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Chen, Z.N. (2007). Antennas for Wearable Devices. Antenna for Portable Devices, John Wiley & Sons Ltd.. [1st ed.].","DOI":"10.1002\/9780470319642"},{"key":"ref_4","unstructured":"Werner, D.H., and Jiang, Z.H. (2016). Metamaterial-Enabled and Microwave Circuit Integrated Wearable Antennas for Off-Body Communications. Electromagnetics of Body Area Networks: Antennas, Propagation and RF Systems, John Wiley & Sons, Inc.. [1st ed.]."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Sayem, A.S.M., Simorangkir, R.B.V.B., Esselle, K.P., Lalbakhsh, A., Gawade, D.R., O\u2019Flynn, B., and Buckley, J.L. (2022). Flexible and Transparent Circularly Polarized Patch Antenna for Reliable Unobtrusive Wearable Wireless Communications. Sensors, 22.","DOI":"10.3390\/s22031276"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2575","DOI":"10.1109\/TAP.2019.2951517","article-title":"Dual-Polarized Embroidered Textile Armband Antenna Array With Omnidirectional Radiation for On-\/Off-Body Wearable Applications","volume":"68","author":"Mao","year":"2020","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"920","DOI":"10.1109\/TBCAS.2017.2671841","article-title":"Compact, Highly Efficient, and Fully Flexible Circularly Polarized Antenna Enabled by Silver Nanowires for Wireless Body-Area Networks","volume":"11","author":"Jiang","year":"2017","journal-title":"IEEE Trans. Biomed. Circuits Syst."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Monti, G., Corchia, L., Paiano, E., De Pascali, G., Tarricone, L., Tomassoni, C., and Sorrentino, R. (2019, January 9\u201315). Textile Wearable Antenna for Firefighters Positioning. Proceedings of the 2019 URSI Asia-Pacific Radio Science Conference (AP-RASC), New Delhi, India.","DOI":"10.23919\/URSIAP-RASC.2019.8738181"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Corchia, L., De Benedetto, E., Monti, G., Cataldo, A., and Tarricone, L. (2017, January 27\u201329). Wearable antennas for applications in remote assistance to elderly people. Proceedings of the 2017 IEEE International Workshop on Measurement and Networking (M&N), Naples, Italy.","DOI":"10.1109\/IWMN.2017.8078400"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Monti, G., Corchia, L., and Tarricone, L. (2014, January 12\u201314). Textile Logo Antennas. Proceedings of the 2014 Mediterranean Microwave Symposium (MMS2014), Marrakech, Marocco.","DOI":"10.1109\/MMS.2014.7088965"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Mikuli\u0107, D., \u0160opp, E., Bonefa\u010di\u0107, D., and \u0160ipu\u0161, Z. (2022). Textile Slotted Waveguide Antennas for Body-Centric Applications. Sensors, 22.","DOI":"10.3390\/s22031046"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Ibanez Labiano, I., Arslan, D., Ozden Yenigun, E., Asadi, A., Cebeci, H., and Alomainy, A. (2021). Screen Printing Carbon Nanotubes Textiles Antennas for Smart Wearables. Sensors, 21.","DOI":"10.3390\/s21144934"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Atanasova, G.L., and Atanasov, N.T. (2020, January 25\u201328). Impact of Electromagnetic Properties of Textile Materials on Performance of a Low-Profile Wearable Antenna Backed by a Reflector. Proceedings of the 2020 International Workshop on Antenna Technology (iWAT), Bucharest, Romania.","DOI":"10.1109\/iWAT48004.2020.1570609739"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Atanasova, G., and Atanasov, N. (2020). Small Antennas for Wearable Sensor Networks: Impact of the Electromagnetic Properties of the Textiles on Antenna Performance. Sensors, 20.","DOI":"10.3390\/s20185157"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Bait-Suwailam, M.M., Labiano, I., and Alomainy, A. (2020). Impedance Enhancement of Textile Grounded Loop Antenna Using High-Impedance Surface (HIS) for Healthcare Applications. Sensors, 20.","DOI":"10.3390\/s20143809"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Zradzi\u0144ski, P., Karpowicz, J., Gryz, K., Morzy\u0144ski, L., M\u0142y\u0144ski, R., Swidzi\u0144ski, A., Godziszewski, K., and Ramos, V. (2020). Modelling the Influence of Electromagnetic Field on the User of a Wearable IoT Device Used in a WSN for Monitoring and Reducing Hazards in the Work Environment. Sensors, 20.","DOI":"10.3390\/s20247131"},{"key":"ref_17","unstructured":"(2019). IEEE Standard for Safety Levels with Respect to Human Exposure to Electric, Magnetic, and Electromagnetic Fields, 0 Hz to 300 GHz. IEEE Std C95.1-2019 (Revision of IEEE Std C95.1-2005\/ Incorporates IEEE Std C95.1-2019\/Cor 1-2019), IEEE."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Balanis, C. (2008). Integrated antennas for wireless personal communications. Modern Antenna Handbook, John Wiley & Sons. [1st ed.].","DOI":"10.1002\/9780470294154"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"International Commission on Non-Ionizing Radiation Protection (ICNIRP) (2020). Guidelines for Limiting Exposure to Electro-magnetic Fields (100 kHz to 300 GHz). Health Phys., 118, 483\u2013524.","DOI":"10.1097\/HP.0000000000001210"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Balanis, C. (2008). Antennas for Biological Experiments. Modern Antenna Handbook, John Wiley & Sons. [1st ed.].","DOI":"10.1002\/9780470294154"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1016\/j.toxlet.2020.01.020","article-title":"Adverse health effects of 5G mobile networking technology under real-life conditions","volume":"323","author":"Kostoff","year":"2020","journal-title":"Toxicol. Lett."},{"key":"ref_22","first-page":"235","article-title":"Effect of electromagnetic field on body weight and blood indices in albino rats and the therapeutic action of vitamin C or E","volume":"20","author":"Shabat","year":"2010","journal-title":"Rom. J. Biophys."},{"key":"ref_23","first-page":"106","article-title":"Modulatory role of grape seed extract on erythrocyte hemolysis and oxidative stress induced by microwave radiation in rats","volume":"10","author":"Hassan","year":"2010","journal-title":"Int. J. Integr. Biol."},{"key":"ref_24","first-page":"317","article-title":"Microwave and thermal interactions with oxidative hemolysis","volume":"16","author":"Kiel","year":"1984","journal-title":"Physiol. Chem. Phys. Med. NMR"},{"key":"ref_25","unstructured":"Ayrapetyan, S.N., and Markov, M.S. (2006). Thermal vs. nonthermal mechanisms of interactions between electromagnetic fields and biological systems. Bioelectromagnetics Current Concepts, Springer. [1st ed.]."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"123","DOI":"10.3109\/15368378.2013.776335","article-title":"Nonthermal electromagnetic fields: From first messenger to therapeutic applications","volume":"32","author":"Pilla","year":"2013","journal-title":"Electromagn. Biol. Med."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1109\/MMM.2020.2999236","article-title":"5G Communication Technology and Coronavirus Disease [Health Matters]","volume":"21","author":"Lin","year":"2020","journal-title":"IEEE Microw. Mag."},{"key":"ref_28","first-page":"S44","article-title":"Study of Erythrocyte Hemolysis on Exposure to Strong 2.45-GHz Electromagnetic Radiation","volume":"50","author":"Kim","year":"2005","journal-title":"Biophysics"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2072","DOI":"10.1109\/22.884197","article-title":"Cell membrane permeabilization of human erythrocytes by athermal 2450-MHz microwave radiation","volume":"48","author":"Sajin","year":"2000","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1067","DOI":"10.1109\/10.704876","article-title":"Finite-difference time-domain analysis of a complete transverse electromagnetic cell loaded with liquid biological media in culture dishes","volume":"45","author":"Popovic","year":"1998","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_31","unstructured":"Kouzmanova, M., Atanasova, G., Atanasov, N., and Tasheva, S. (2006, January 16\u201320). Alterations in hemolysis after in vitro exposure of human erythrocytes to GSM900 electromagnetic field. Proceedings of the 4th International Workshop \u201cBiological Effects of EMF\u201d, Crete, Greece."},{"key":"ref_32","unstructured":"(2006). IEEE Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz. IEEE Std C95.1-2005 (Revision of IEEE Std C95.1-1991), IEEE."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Andrews, E.F., Lim, H.B., Xiao, D., Khamas, S., Starke, P.L., Ang, S.P., Barker, A.T., Cook, G.G., Coulton, L.A., and Scutt, A. (2004, January 25\u201326). Investigation of SAR uniformity in TEM cell exposed culture media. Proceedings of the 2004 IEE Antenna Measurements and SAR, AMS 2004, Loughborough, UK.","DOI":"10.1049\/ic:20040080"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"429","DOI":"10.1007\/s10867-011-9224-x","article-title":"Visualization study of motion and deformation of red blood cells in a microchannel with straight, divergent and convergent sections","volume":"37","author":"Chen","year":"2011","journal-title":"J. Biol. Phys."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"298","DOI":"10.1152\/advan.00083.2016","article-title":"Measuring osmosis and hemolysis of red blood cells","volume":"41","author":"Goodhead","year":"2017","journal-title":"Adv. Physiol. Educ."},{"key":"ref_36","unstructured":"Prastalo, R., Tesanovic, G., and Sukalo, S. (2003, January 1\u20133). Mechanism of mobile phone radiation acting on biological systems. Proceedings of the 6th International Conference on Telecommunications in Modern Satellite, Cable and Broadcasting Service, 2003. TELSIKS 2003, Nis, Yugoslavia."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1007\/s10669-007-9078-8","article-title":"Effects of in vitro exposure to GSM900 electromagnetic field on human erythrocytes","volume":"27","author":"Kouzmanova","year":"2007","journal-title":"Environmentalist"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Sajin, G., Al, D., Savopol, T., Roxana, M., and Eugenia, K. (1995, January 4). 2.45 GHz microwave radiation effects in nonthermal damaging of the human erythrocyte membrane. Proceedings of the 1995 25th European Microwave Conference, Bologna, Italy.","DOI":"10.1109\/EUMA.1995.337081"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"George, S., Ion, R., Eugenia, K., Tudor, S., Alexandru, D., and Maria, S. (1997, January 8\u201312). Low Power Microwave Effects on Erythrocyte Membranes. Proceedings of the 1997 27th European Microwave Conference, Jerusalem, Israel.","DOI":"10.1109\/EUMA.1997.337866"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"10798","DOI":"10.1038\/s41598-017-11288-9","article-title":"The effect of a high frequency electromagnetic field in the microwave range on red blood cells","volume":"7","author":"Nguyen","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1002\/bem.20226","article-title":"Effects of a 2450 MHz high-frequency electromagnetic field with a wide range of SARs on the induction of heat-shock proteins in A172 cells","volume":"27","author":"Wang","year":"2006","journal-title":"Bioelectromagnetics"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1093\/jrr\/rrt106","article-title":"Adaptive response in human blood lymphocytes exposed to non-ionizing radiofrequency fields: Resistance to ionizing radiation-induced damage","volume":"55","author":"Sannino","year":"2014","journal-title":"J. Radiat. Res."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Paolini, G., Masotti, D., and Costanzo, A. (2018, January 10\u201313). Simulated Effects of Specific Absorption Rate and Thermal Variations on Keratinocytes and Epidermis Exposed to Radio-Frequency. Proceedings of the 2018 EMF-Med 1st World Conference on Biomedical Applications of Electromagnetic Fields (EMF-Med), Split, Croatia.","DOI":"10.23919\/EMF-MED.2018.8526054"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/14\/5139\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:46:41Z","timestamp":1760140001000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/14\/5139"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,7,8]]},"references-count":43,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2022,7]]}},"alternative-id":["s22145139"],"URL":"https:\/\/doi.org\/10.3390\/s22145139","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,7,8]]}}}