[{"quality_controlled":"1","title":"Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges","file_date_updated":"2026-05-11T20:34:29Z","date_created":"2026-05-11T20:35:02Z","volume":6,"file":[{"access_level":"open_access","file_id":"6902","relation":"main_file","content_type":"application/pdf","file_name":"_2026_Blachowicz_Micro6_35.pdf","file_size":6220358,"date_created":"2026-05-11T20:34:29Z","creator":"aehrmann","date_updated":"2026-05-11T20:34:29Z","success":1}],"type":"journal_article","publication_identifier":{"eissn":["2673-8023"]},"user_id":"220548","publication":"Micro","status":"public","intvolume":"         6","doi":"10.3390/micro6020035","year":"2026","abstract":[{"lang":"eng","text":"Freeform optics belong to the increasingly important elements in optical research and industry, which pose several challenges regarding design and highly precise manufacturing. First being used in cameras and for focusing, nowadays freeform optics are used in a broad range of applications, from lighting to LiDAR, from endoscopy to photovoltaics, and from astronomical instruments to quantum cryptography. Designing freeform optics can be based on different theories and methods. Fabrication is possible by mechanical methods, such as diamond turning or high-precision milling, often followed by different polishing techniques, as well as laser-based techniques, mainly applying different lithographic techniques. Here, we give an overview of recent design and optimization methods, production methods used during the last years, and applications of freeform optics, including the possibility to combine freeform optics with tunability for different applications. We describe the opportunities of new applications as well as common problems and give an outlook towards future directions of research and development."}],"article_number":"35","article_type":"review","tmp":{"short":"CC BY (4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png"},"has_accepted_license":"1","project":[{"_id":"0ec202b7-cd76-11ed-89f4-a9e1a6dbdaa7","name":"Institut für Technische Energie-Systeme"}],"oa":"1","publication_status":"published","issue":"2","keyword":["photopolymerization","tunable micro-optical freeform elements","two-photon polymerization","multiphoton lithography","direct laser writing","diamond turning"],"urn":"urn:nbn:de:hbz:bi10-69017","citation":{"short":"T. Blachowicz, G. Ehrmann, J. Fiedler, R. Kaschuba, A. Ehrmann, Micro 6 (2026).","chicago":"Blachowicz, Tomasz, Guido Ehrmann, Johannes Fiedler, Reinhard Kaschuba, and Andrea Ehrmann. “Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges.” <i>Micro</i> 6, no. 2 (2026). <a href=\"https://doi.org/10.3390/micro6020035\">https://doi.org/10.3390/micro6020035</a>.","ama":"Blachowicz T, Ehrmann G, Fiedler J, Kaschuba R, Ehrmann A. Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges. <i>Micro</i>. 2026;6(2). doi:<a href=\"https://doi.org/10.3390/micro6020035\">10.3390/micro6020035</a>","mla":"Blachowicz, Tomasz, et al. “Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges.” <i>Micro</i>, vol. 6, no. 2, 35, MDPI AG, 2026, doi:<a href=\"https://doi.org/10.3390/micro6020035\">10.3390/micro6020035</a>.","ieee":"T. Blachowicz, G. Ehrmann, J. Fiedler, R. Kaschuba, and A. Ehrmann, “Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges,” <i>Micro</i>, vol. 6, no. 2, 2026.","bibtex":"@article{Blachowicz_Ehrmann_Fiedler_Kaschuba_Ehrmann_2026, title={Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges}, volume={6}, DOI={<a href=\"https://doi.org/10.3390/micro6020035\">10.3390/micro6020035</a>}, number={235}, journal={Micro}, publisher={MDPI AG}, author={Blachowicz, Tomasz and Ehrmann, Guido and Fiedler, Johannes and Kaschuba, Reinhard and Ehrmann, Andrea}, year={2026} }","apa":"Blachowicz, T., Ehrmann, G., Fiedler, J., Kaschuba, R., &#38; Ehrmann, A. (2026). Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges. <i>Micro</i>, <i>6</i>(2). <a href=\"https://doi.org/10.3390/micro6020035\">https://doi.org/10.3390/micro6020035</a>","alphadin":"<span style=\"font-variant:small-caps;\">Blachowicz, Tomasz</span> ; <span style=\"font-variant:small-caps;\">Ehrmann, Guido</span> ; <span style=\"font-variant:small-caps;\">Fiedler, Johannes</span> ; <span style=\"font-variant:small-caps;\">Kaschuba, Reinhard</span> ; <span style=\"font-variant:small-caps;\">Ehrmann, Andrea</span>: Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges. In: <i>Micro</i> Bd. 6, MDPI AG (2026), Nr. 2"},"author":[{"last_name":"Blachowicz","full_name":"Blachowicz, Tomasz","first_name":"Tomasz"},{"first_name":"Guido","full_name":"Ehrmann, Guido","last_name":"Ehrmann"},{"first_name":"Johannes","full_name":"Fiedler, Johannes","last_name":"Fiedler"},{"first_name":"Reinhard","last_name":"Kaschuba","full_name":"Kaschuba, Reinhard"},{"first_name":"Andrea","orcid_put_code_url":"https://api.orcid.org/v2.0/0000-0003-0695-3905/work/214321986","id":"223776","orcid":"0000-0003-0695-3905","full_name":"Ehrmann, Andrea","last_name":"Ehrmann"}],"publisher":"MDPI AG","date_updated":"2026-05-12T05:18:08Z","_id":"6901","language":[{"iso":"eng"}]},{"citation":{"chicago":"Mpofu, Nonsikelelo Sheron, Tomasz Blachowicz, Andrea Ehrmann, and Guido Ehrmann. “Wearable Electrospun Nanofibrous Sensors for Health Monitoring.” <i>Micro</i> 4, no. 4 (2024): 798–822. <a href=\"https://doi.org/10.3390/micro4040049\">https://doi.org/10.3390/micro4040049</a>.","short":"N.S. Mpofu, T. Blachowicz, A. Ehrmann, G. Ehrmann, Micro 4 (2024) 798–822.","ama":"Mpofu NS, Blachowicz T, Ehrmann A, Ehrmann G. Wearable Electrospun Nanofibrous Sensors for Health Monitoring. <i>Micro</i>. 2024;4(4):798-822. doi:<a href=\"https://doi.org/10.3390/micro4040049\">10.3390/micro4040049</a>","mla":"Mpofu, Nonsikelelo Sheron, et al. “Wearable Electrospun Nanofibrous Sensors for Health Monitoring.” <i>Micro</i>, vol. 4, no. 4, MDPI AG, 2024, pp. 798–822, doi:<a href=\"https://doi.org/10.3390/micro4040049\">10.3390/micro4040049</a>.","ieee":"N. S. Mpofu, T. Blachowicz, A. Ehrmann, and G. Ehrmann, “Wearable Electrospun Nanofibrous Sensors for Health Monitoring,” <i>Micro</i>, vol. 4, no. 4, pp. 798–822, 2024.","apa":"Mpofu, N. S., Blachowicz, T., Ehrmann, A., &#38; Ehrmann, G. (2024). Wearable Electrospun Nanofibrous Sensors for Health Monitoring. <i>Micro</i>, <i>4</i>(4), 798–822. <a href=\"https://doi.org/10.3390/micro4040049\">https://doi.org/10.3390/micro4040049</a>","bibtex":"@article{Mpofu_Blachowicz_Ehrmann_Ehrmann_2024, title={Wearable Electrospun Nanofibrous Sensors for Health Monitoring}, volume={4}, DOI={<a href=\"https://doi.org/10.3390/micro4040049\">10.3390/micro4040049</a>}, number={4}, journal={Micro}, publisher={MDPI AG}, author={Mpofu, Nonsikelelo Sheron and Blachowicz, Tomasz and Ehrmann, Andrea and Ehrmann, Guido}, year={2024}, pages={798–822} }","alphadin":"<span style=\"font-variant:small-caps;\">Mpofu, Nonsikelelo Sheron</span> ; <span style=\"font-variant:small-caps;\">Blachowicz, Tomasz</span> ; <span style=\"font-variant:small-caps;\">Ehrmann, Andrea</span> ; <span style=\"font-variant:small-caps;\">Ehrmann, Guido</span>: Wearable Electrospun Nanofibrous Sensors for Health Monitoring. In: <i>Micro</i> Bd. 4, MDPI AG (2024), Nr. 4, S. 798–822"},"author":[{"first_name":"Nonsikelelo Sheron","last_name":"Mpofu","full_name":"Mpofu, Nonsikelelo Sheron"},{"first_name":"Tomasz","full_name":"Blachowicz, Tomasz","last_name":"Blachowicz"},{"orcid":"0000-0003-0695-3905","full_name":"Ehrmann, Andrea","last_name":"Ehrmann","first_name":"Andrea","orcid_put_code_url":"https://api.orcid.org/v2.0/0000-0003-0695-3905/work/176200463","id":"223776"},{"full_name":"Ehrmann, Guido","last_name":"Ehrmann","first_name":"Guido"}],"date_updated":"2026-03-17T15:29:17Z","publisher":"MDPI AG","_id":"5334","language":[{"iso":"eng"}],"article_type":"review","oa":"1","tmp":{"short":"CC BY (4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png"},"project":[{"name":"Institut für Technische Energie-Systeme","_id":"0ec202b7-cd76-11ed-89f4-a9e1a6dbdaa7"}],"has_accepted_license":"1","keyword":["wearables","electrospinning","health monitoring","ECG","heartbeat","strain sensors","temperature sensors","light sensors"],"urn":"urn:nbn:de:hbz:bi10-53346","issue":"4","publication_status":"published","status":"public","doi":"10.3390/micro4040049","intvolume":"         4","page":"798-822","year":"2024","quality_controlled":"1","date_created":"2025-01-20T14:11:23Z","title":"Wearable Electrospun Nanofibrous Sensors for Health Monitoring","file_date_updated":"2025-01-20T14:10:39Z","volume":4,"type":"journal_article","publication_identifier":{"eissn":["2673-8023"]},"file":[{"access_level":"open_access","relation":"main_file","file_id":"5335","content_type":"application/pdf","file_size":17602640,"file_name":"_2024_Mpofu_Micro4_798-822.pdf","date_created":"2025-01-20T14:10:39Z","creator":"aehrmann","success":1,"date_updated":"2025-01-20T14:10:39Z"}],"user_id":"220548","publication":"Micro"},{"author":[{"last_name":"Blachowicz","full_name":"Blachowicz, Tomasz","first_name":"Tomasz"},{"first_name":"Ilda","last_name":"Kola","full_name":"Kola, Ilda"},{"orcid":"0000-0003-0695-3905","full_name":"Ehrmann, Andrea","last_name":"Ehrmann","first_name":"Andrea","orcid_put_code_url":"https://api.orcid.org/v2.0/0000-0003-0695-3905/work/157388173","id":"223776"},{"last_name":"Guenther","full_name":"Guenther, Karoline","first_name":"Karoline"},{"first_name":"Guido","full_name":"Ehrmann, Guido","last_name":"Ehrmann"}],"citation":{"mla":"Blachowicz, Tomasz, et al. “Magnetic Micro and Nano Sensors for Continuous Health Monitoring.” <i>Micro</i>, vol. 4, no. 2, MDPI AG, 2024, pp. 206–28, doi:<a href=\"https://doi.org/10.3390/micro4020015\">10.3390/micro4020015</a>.","ama":"Blachowicz T, Kola I, Ehrmann A, Guenther K, Ehrmann G. Magnetic Micro and Nano Sensors for Continuous Health Monitoring. <i>Micro</i>. 2024;4(2):206-228. doi:<a href=\"https://doi.org/10.3390/micro4020015\">10.3390/micro4020015</a>","chicago":"Blachowicz, Tomasz, Ilda Kola, Andrea Ehrmann, Karoline Guenther, and Guido Ehrmann. “Magnetic Micro and Nano Sensors for Continuous Health Monitoring.” <i>Micro</i> 4, no. 2 (2024): 206–28. <a href=\"https://doi.org/10.3390/micro4020015\">https://doi.org/10.3390/micro4020015</a>.","short":"T. Blachowicz, I. Kola, A. Ehrmann, K. Guenther, G. Ehrmann, Micro 4 (2024) 206–228.","alphadin":"<span style=\"font-variant:small-caps;\">Blachowicz, Tomasz</span> ; <span style=\"font-variant:small-caps;\">Kola, Ilda</span> ; <span style=\"font-variant:small-caps;\">Ehrmann, Andrea</span> ; <span style=\"font-variant:small-caps;\">Guenther, Karoline</span> ; <span style=\"font-variant:small-caps;\">Ehrmann, Guido</span>: Magnetic Micro and Nano Sensors for Continuous Health Monitoring. In: <i>Micro</i> Bd. 4, MDPI AG (2024), Nr. 2, S. 206–228","bibtex":"@article{Blachowicz_Kola_Ehrmann_Guenther_Ehrmann_2024, title={Magnetic Micro and Nano Sensors for Continuous Health Monitoring}, volume={4}, DOI={<a href=\"https://doi.org/10.3390/micro4020015\">10.3390/micro4020015</a>}, number={2}, journal={Micro}, publisher={MDPI AG}, author={Blachowicz, Tomasz and Kola, Ilda and Ehrmann, Andrea and Guenther, Karoline and Ehrmann, Guido}, year={2024}, pages={206–228} }","apa":"Blachowicz, T., Kola, I., Ehrmann, A., Guenther, K., &#38; Ehrmann, G. (2024). Magnetic Micro and Nano Sensors for Continuous Health Monitoring. <i>Micro</i>, <i>4</i>(2), 206–228. <a href=\"https://doi.org/10.3390/micro4020015\">https://doi.org/10.3390/micro4020015</a>","ieee":"T. Blachowicz, I. Kola, A. Ehrmann, K. Guenther, and G. Ehrmann, “Magnetic Micro and Nano Sensors for Continuous Health Monitoring,” <i>Micro</i>, vol. 4, no. 2, pp. 206–228, 2024."},"publisher":"MDPI AG","date_updated":"2026-03-17T15:29:01Z","language":[{"iso":"eng"}],"_id":"4455","article_type":"review","main_file_link":[{"open_access":"1"}],"tmp":{"short":"CC BY (4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png"},"project":[{"_id":"0ec202b7-cd76-11ed-89f4-a9e1a6dbdaa7","name":"Institut für Technische Energie-Systeme"}],"has_accepted_license":"1","oa":"1","publication_status":"published","issue":"2","urn":"urn:nbn:de:hbz:bi10-44557","keyword":["Hall effect","giant magnetoresistance","tunnel magnetoresistance","anisotropic magnetoresistance","giant magnetoimpedance"],"status":"public","page":"206-228","intvolume":"         4","doi":"10.3390/micro4020015","year":"2024","quality_controlled":"1","volume":4,"file_date_updated":"2024-04-11T02:02:06Z","title":"Magnetic Micro and Nano Sensors for Continuous Health Monitoring","date_created":"2024-04-11T02:05:34Z","user_id":"220548","file":[{"date_updated":"2024-04-11T02:02:06Z","success":1,"date_created":"2024-04-11T02:02:06Z","creator":"aehrmann","file_name":"micro-04-00015.pdf","file_size":5149724,"content_type":"application/pdf","relation":"main_file","file_id":"4456","access_level":"open_access"}],"publication_identifier":{"eissn":["2673-8023"]},"type":"journal_article","publication":"Micro"}]