{"id":113917,"date":"2020-10-05T16:25:31","date_gmt":"2020-10-05T23:25:31","guid":{"rendered":"https:\/\/lifeboat.com\/blog\/2020\/10\/giant-electrochemical-actuation-in-a-nanoporous-silicon-polypyrrole-hybrid-material"},"modified":"2020-10-07T01:34:57","modified_gmt":"2020-10-07T08:34:57","slug":"giant-electrochemical-actuation-in-a-nanoporous-silicon-polypyrrole-hybrid-material","status":"publish","type":"post","link":"https:\/\/lifeboat.com\/blog\/2020\/10\/giant-electrochemical-actuation-in-a-nanoporous-silicon-polypyrrole-hybrid-material","title":{"rendered":"Giant electrochemical actuation in a nanoporous silicon-polypyrrole hybrid material"},"content":{"rendered":"<p><a class=\"aligncenter blog-photo\" href=\"https:\/\/lifeboat.com\/blog.images\/giant-electrochemical-actuation-in-a-nanoporous-silicon-polypyrrole-hybrid-material.jpg\"><\/a><\/p>\n<p>The absence of piezoelectricity in silicon makes direct electromechanical applications of this mainstream semiconductor impossible. Integrated electrical control of the silicon mechanics, however, would open up new perspectives for on-chip actuorics. Here, we combine wafer-scale nanoporosity in single-crystalline silicon with polymerization of an artificial muscle material inside pore space to synthesize a composite that shows macroscopic electrostrain in aqueous electrolyte. The voltage-strain coupling is three orders of magnitude larger than the best-performing ceramics in terms of piezoelectric actuation. We trace this huge electroactuation to the concerted action of 100 billions of nanopores per square centimeter cross section and to potential-dependent pressures of up to 150 atmospheres at the single-pore scale. The exceptionally small operation voltages (0.4 to 0.9 volts), along with the sustainable and biocompatible base materials, make this hybrid promising for bioactuator applications.<\/p>\n<p>An electrochemical change in the oxidation state of polypyrrole (PPy) can increase or decrease the number of delocalized charges in its polymer backbone (<a id=\"xref-ref-1-1\" class=\"\" href=\"https:\/\/advances.sciencemag.org\/content\/6\/40\/eaba1483#ref-1\"><em>1<\/em><\/a>). Immersed in an electrolyte, this is also accompanied by a reversible counter-ion uptake or expulsion and thus with a marcroscopic contraction or swelling under electrical potential control, making PPy one of the most used artificial muscle materials (<a id=\"xref-ref-1-2\" class=\"\" href=\"https:\/\/advances.sciencemag.org\/content\/6\/40\/eaba1483#ref-1\"><em>1<\/em><\/a>\u2013<a id=\"xref-ref-5-1\" class=\"\" href=\"https:\/\/advances.sciencemag.org\/content\/6\/40\/eaba1483#ref-5\"><em>5<\/em><\/a>).<\/p>\n<p>Here, we combine this actuator polymer with the three-dimensional (3D) scaffold structure of nanoporous silicon (<a id=\"xref-ref-6-1\" class=\"\" href=\"https:\/\/advances.sciencemag.org\/content\/6\/40\/eaba1483#ref-6\"><em>6<\/em><\/a>\u2013<a id=\"xref-ref-8-1\" class=\"\" href=\"https:\/\/advances.sciencemag.org\/content\/6\/40\/eaba1483#ref-8\"><em>8<\/em><\/a>) to design, similarly as found in many multiscale biological composites in nature (<a id=\"xref-ref-9-1\" class=\"\" href=\"https:\/\/advances.sciencemag.org\/content\/6\/40\/eaba1483#ref-9\"><em>9<\/em><\/a>), a material with embedded electrochemical actuation that consists of a few light and abundant elemental constituents (i.e., H, C, N, O, Si, and Cl).<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The absence of piezoelectricity in silicon makes direct electromechanical applications of this mainstream semiconductor impossible. Integrated electrical control of the silicon mechanics, however, would open up new perspectives for on-chip actuorics. Here, we combine wafer-scale nanoporosity in single-crystalline silicon with polymerization of an artificial muscle material inside pore space to synthesize a composite that shows [\u2026]<\/p>\n","protected":false},"author":427,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,19,1523,1499,17],"tags":[],"class_list":["post-113917","post","type-post","status-publish","format-standard","hentry","category-biological","category-chemistry","category-computing","category-cyborgs","category-sustainability"],"_links":{"self":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/113917","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/users\/427"}],"replies":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/comments?post=113917"}],"version-history":[{"count":1,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/113917\/revisions"}],"predecessor-version":[{"id":113983,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/113917\/revisions\/113983"}],"wp:attachment":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/media?parent=113917"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/categories?post=113917"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/tags?post=113917"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}