Highly sensitive self-powered pressure sensor and the use of the same
View Patent ↗Provided is a self-powered pressure sensor which may show excellent pressure sensitivity by significantly improving transfer efficiency of charges generated by triboelectrification, the sensor including: a first electrode; a first triboelectrification unit positioned on the first electrode; a second triboelectrification unit including a pattern on which a microstructure is repeatedly positioned, the microstructure being reversibly in contact with or separated from the first triboelectrification unit by a physical external force, and having at least one surface in contact with the first triboelectrification unit to induce a change in a contact area; and a second electrode positioned inside the second triboelectrification unit and conformally positioned on a surface of the microstructure, wherein the first electrode and the second electrode are geometrically asymmetric to each other.
1 . A self-powered pressure sensor comprising:
a first electrode;
a first triboelectrification unit positioned on the first electrode;
a second triboelectrification unit comprising a microstructure pattern including a plurality of microstructures, each microstructure being reversibly in contact with or separated from the first triboelectrification unit by a physical external force, and having at least one surface in contact with the first triboelectrification unit to induce a change in a contact area; and
a second electrode positioned inside the second triboelectrification unit, the second electrode comprising an electrode layer positioned on a surface of the microstructure and having a structure parallel to the surface of the microstructure,
wherein the first electrode and the second electrode are geometrically asymmetric to each other.
2 . The sensor of claim 1 , wherein the microstructure has any one selected from the group consisting of sphere, hemisphere, cone, truncated cone, polygonal pyramid, and truncated polygonal pyramid shapes.
3 . The sensor of claim 2 , wherein the microstructure has the hemisphere or the truncated cone shape.
4 . The sensor of claim 3 , wherein the microstructure has the hemisphere shape.
5 . The sensor of claim 4 , wherein a microstructure diameter is 200 to 2000 μm and a microstructure height is 100 to 3000 μm.
6 . The sensor of claim 1 , wherein the first electrode has a flat structure.
7 . The sensor of claim 1 , wherein the first triboelectrification unit and the second triboelectrification unit include different materials.
8 . The sensor of claim 1 , wherein the first triboelectrification unit includes any one selected from the group consisting of fluorinated ethylene-propylene copolymer (FEP), polyvinylidene fluoride (PVDF), perfluoroalkoxy alkane (PFA), and ethylene-tetrafluoroethylene copolymer (ETEF).
9 . The sensor of claim 1 , wherein the second triboelectrification unit includes a siloxane-based polymer.
10 . The sensor of claim 1 , wherein the second electrode includes a metal nanowire.
11 . The sensor of claim 1 , wherein a separation distance between the surface of the microstructure and the second electrode is 1 to 30 μm.
12 . The sensor of claim 11 , wherein a thickness of the second electrode is 0.5 to 2 μm.
13 . The sensor of claim 12 , wherein a ratio of the thickness of the second electrode to the separation distance between the surface of the microstructure and the second electrode is 1:1 to 30.
14 . The sensor of claim 1 , wherein elastic modulus of the first triboelectrification unit is 10 2 times or more than that of the second triboelectrification unit.
15 . The sensor of claim 1 , wherein the microstructure is repeatedly positioned on the pattern for a ratio of a microstructure diameter to a separation distance between the closest microstructures to be 1:0.25 to 2.
16 . The sensor of claim 1 , wherein the self-powered pressure sensor has pressure sensitivity of 0.1 to 5 V/kPa when a pressure is applied thereto.