A PRINTING METHOD OF MANUFACTURING NANOBEAM STRUCTURES

Abstract

A method of manufacturing a nanobeam structure by printing, namely coaxial focused electrohydrodynamic jet printing. In this method, under the combined action of electric field, thermal field and flow field, a stable coaxial jet is formed and used to print linear bilayer encapsulated structure on a substrate with a prefabricated support structure. Within the coaxial jet, the nanoscale inner liquid consisting of functional material is encapsulated by the microscale outer liquid consisting of high viscous material, which has the capability to directly print functional nanobeam structures. This high viscous material eliminates the disturbance of external micro-environment, and plays a role of supporting the printed inner structure before complete solidification of the inner material. A nanobeam structure only consisting of inner function material is formed on the substrate when the outer high viscous encapsulated material is removed.

Claims

1. A printing method of manufacturing nanobeam structures, comprising the following steps: preparing a substrate, wherein the nanobeam structure mainly includes a nano-freebeam and a nano-cantilever beam, so the substrates are prepared according to the form of nanobeams; the substrate used to print the nano-cantilever beam is of a high temperature resistance flat-plate structure, and the substrate used to print the nano-freebeam is of a high temperature resistance flat-plate structure with a prefabricated trench of a certain high aspect; the trench is prepared by means of micro/nano processing techniques of photolithograph, etching, ion beam and so on; subsequently, an electrode is prepared on the substrate by using magnetron sputtering, vapor deposition and electroforming; forming a coaxial jet, wherein, according to the requirements for the nanobeam structure material, an inner function material and an outer high viscous material are injected in a coaxial needle by two micro syringe pumps, respectively; the coaxial needle is connected to a high voltage power supply; a stable coaxial jet on the tip of the coaxial needle can be obtained under the working parameters of the flow rate of an inner liquid at a range of 1 pL/min-5 pL/min, the flow rate of an outer liquid at the range of 100 nL/min-150 nL/min, an applied voltage at the range of 500 V to 1000 V, and a coaxial needle-substrate distance at the range of 500 pan-1 mm; and printing of nanobeam structure, wherein the substrate is fixed on a motion stage by a vacuum adsorption device, which is moved at the speed of 80 mm/s-100 mm/s; the substrate is perpendicular to the coaxial needle, a linear bilayer encapsulated structure consisting of an inner function material and an outer high viscous material can be obtained when the coaxial jet is printed on the substrate; after printing, under the effect of a thermal field, the inner function liquid and outer high viscous liquid are solidified and semi-solidified respectively, and the semi-solidified outer high viscous liquid plays a role of supporting an inner nanobeam structure; finally, a nanobeam structure only consisting of inner function material is formed on the substrate when the outer high viscous material is removed by the methods of pyrolysis or solution dissolution.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1. Schematic diagram of the printing device.

[0015] FIG. 2. The process flow diagram of printing nanobeam.

[0016] Legends: 1. X-Y motion stage; 2. High-voltage power supply; 3. Coaxial needle; 4. Micro syringe pump;

[0017] 5. Micro syringe pump; 6. Substrate with prefabricated support structure; 7. Coaxial cone-jet; 8. Microscale outer encapsulated structure;

[0018] 9. Nanoscale inner function structure; 10. Nanobeam.

DETAILED DESCRIPTION

[0019] Specific implementation of the present invention is described in detail combining with the technical schemes and explained drawings. The example mainly includes substrate preparation, formation of coaxial jet, and manufacturing of nanobeam structure by printing.

[0020] The specific implementation steps of the example are as follows:

[0021] (1). Substrate Preparation

[0022] A single side polished monocrystalline silicon wafer is oxidized in a tubular furnace for 3.5 hours. Then a trench with width of 20 m and depth of 5 m is prepared on the surface of the oxidized silicon wafer by using photolithography and wet etching techniques. Subsequently, a pair of platinum electrodes with the thickness of 200 nm are deposited on both sides of the trench by using photolithograph, magnetron sputtering and lift off techniques.

[0023] (2). Formation of Coaxial Jet

[0024] The selected inner function material of PZT sol and outer high viscous material of silicone oil are injected in the coaxial needle (3) by micro syringes pumps (4), (5), respectively. The coaxial needle is connected to a high-voltage power supply (2). A stable coaxial cone-jet (7) consisting of inner function material of PZT sol and outer high viscous encapsulated material of silicone oil can be formed when the working parameters of the flow rate of inner material, flow rate of outer material, applied voltage, coaxial needle-substrate distance are set to 2 pL/min, 1 nL/min, 600 V, and 600 m, respectively.

[0025] (3). Printing of Nanobeam Structure

[0026] The substrate with a prefabricated trench (6) is fixed to the motion stage (1) by using a vacuum adsorption device. The substrate is perpendicular to the coaxial needle, a linear bilayer encapsulated structure consisting of inner function material of PZT and outer high viscous material of silicone oil can be obtained when the coaxial jet print on the substrate. During printing process, the substrate moves with the motion stage at a speed of 100 mm/s. After printing, under the effect of thermal field, the nanoscale inner function material of PZT (9) and microscale outer high viscous encapsulated material of silicone oil (8) are solidified and semi-solidified respectively, and the semi-solidified outer high viscous material of silicone oil plays a role of supporting the inner PZT nanobeam structure. Finally, a PZT nanobeam structure (10) only consisting the inner function material of PZT is formed on the substrate when the outer high viscous material of silicone oil is removed by the methods of pyrolysis or solution dissolution.

[0027] The present invention proposes a method of manufacturing the nanobeam structure by printing, named coaxial focused electrohydrodynamic jet printing. In this method, under the combined action of electric field, thermal field and flow field, a stable coaxial jet is formed and used to print linear bilayer encapsulated structure on a substrate with a prefabricated support structure. Within the coaxial jet, the nanoscale inner liquid consisting of functional material is encapsulated by the microscale outer liquid consisting of high viscous material, which has the capability to directly print functional nanobeam structures. This high viscous material eliminates the disturbance of external micro-environment, and plays a role of supporting the printed inner structure before complete solidification of the inner material. A nanobeam structure only consisting of inner function material is formed on the substrate when the outer high viscous encapsulated material is removed. The advantages of manufacturing nanobeam structures by coaxial focused electrohydrodynamic jet printing technique include simple process, high consistency and high efficiency. Thereby, this method provides an effective method for nanostructure fabrication with low cost and rapid manufacturing.