CN104690969B - Bionic irregular micro nano composite structure manufacturing process based on 3D ejection printing technique - Google Patents

Abstract

The invention discloses a manufacturing process of a bionic special-shaped micro-nano composite structure based on 3D jet printing technology. The process steps are as follows: 1. Master plate patterning step; 2. 3D jet printing step; 3. Base preparation step; 4. Transfer Imprint step. The invention can be used to realize the micro-nano composite structure of the "gecko belt", and has the advantages of high efficiency, low cost, large-area preparation potential and the like.

Description

Manufacturing process of biomimetic shaped micro-nano composite structure based on 3D jet printing technology

technical field

The invention relates to 3D printing, in particular to a manufacturing process of a bionic special-shaped micro-nano composite structure based on 3D jet printing technology.

Background technique

Geckos can walk freely on smooth walls, and can stick upside down to the ceiling. This is because there is a special adhesive force between the gecko's feet and the surface of the interacting object, but the mechanism of this adhesive force has become a difficult mystery for centuries.

Russell and Ruibal discovered through scanning electron microscopy that there are about 500,000 tiny setae growing on the bottom of each foot of the gecko, and the size of each setae is about 30-130 μm. American scientists Autumn et al. have found through experimental research that the micro-nano composite bristle structure and the contact surface molecules are very small, resulting in "Van der Waals force". Although the adhesive force produced by each setae is very weak, the sum of millions of setae is enough to support the gecko's body. The potential uses of this bionic "gecko belt" are many, such as safety devices used by climbers, high-adhesive gloves used by goalkeepers, and medical bandages that can be easily adhered only by "Van der Waals force". However, in the current bionic "gecko belt" manufacturing process, there are complex processes (such as the need to make masks, photolithography, and mold turning), high costs (such as polysilicon, ICP etching), and poor process repeatability. The problem of large area preparation.

Therefore, it is necessary to propose a micro-nano composite structure manufacturing process that can realize the "gecko belt" structure and has the advantages of high efficiency, low cost, and large-area preparation potential.

Contents of the invention

In view of this, the present invention provides a bionic special-shaped micro-nano composite structure manufacturing process based on 3D jet printing technology, which includes:

(a) master patterning step, preparing microstructures on the single crystal silicon master by photolithography and deep dry etching process;

(b) a jet printing step, first performing a low surface energy treatment on the patterned substrate in step (a), then depositing a resin microlens array on the substrate through a jet printing process, and performing ultraviolet curing;

(c) Prepare the substrate step, coat the UV-curable resin on another substrate, select the same resin material as in step (b);

(d) transfer embossing step, the substrate obtained in step (c) is docked with the master plate treated in step (b) and transferred and imprinted, a certain pressure is applied, ultraviolet curing is carried out, and then the mold is demoulded, and the final master plate The resin material is transferred to the substrate.

The above-mentioned manufacturing process combining 3D jet printing technology and nano transfer imprinting technology has the advantages of high efficiency and low cost, and has the prospect of large-area preparation.

Description of drawings

Figures 1a to 1d are a flow chart of preparing submicron structures on a master plate according to an embodiment of the present invention, wherein:

Figure 1a is the spin-coating electron beam glue process, Figure 1b is the electron beam exposure process, Figure 1c is the deep dry etching process, and Figure 1d is the film removal process; 11 is the single crystal silicon master, 12 is the electron beam glue, 13 14 is the electron beam gel after development, and 14 is the single crystal silicon after deep dry etching;

Fig. 2 is the jet printing preparation microlens array flow chart shown in an embodiment of the present invention, wherein: Fig. 2 a is the low surface energy treatment process, Fig. 2 b jet printing process; 21 is the patterned silicon master plate, 22 is the low surface Energy C4F8 layer, 23 is a resin microlens array;

Fig. 3 is the flow chart of transfer embossing shown in an embodiment of the present invention, wherein: Fig. 3 a is the UV-curable glue spinning process, Fig. 3 b is the transfer embossing step, Fig. 3 c is the demoulding step; 31 is the quartz substrate, 32 is an ultraviolet curable resin, and 33 is a resin transferred by embossing;

Fig. 4 is a scanning electron microscope image of a micro-nano composite structure prepared by transfer imprinting on a quartz substrate according to an embodiment of the present invention.

detailed description

In one embodiment, the present invention discloses a biomimetic special-shaped micro-nano composite structure manufacturing process based on 3D jet printing technology, the process includes:

(a) master patterning step, preparing microstructures on the single crystal silicon master by photolithography and deep dry etching process;

(b) a jet printing step, first performing a low surface energy treatment on the patterned substrate in step (a), then depositing a resin microlens array on the substrate through a jet printing process, and performing ultraviolet curing;

(c) Prepare the substrate step, coat the UV-curable resin on another substrate, select the same resin material as in step (b);

(d) transfer embossing step, the substrate obtained in step (c) is docked with the master plate treated in step (b) and transferred and imprinted, a certain pressure is applied, ultraviolet curing is carried out, and then the mold is demoulded, and the final master plate The resin material is transferred to the substrate.

For this example, the above-mentioned process steps are used to prepare the biomimetic micro-nano composite structure, which can transfer structures with different characteristic sizes to the UV-curable adhesive at one time, and the two-stage structure is the same material, which has strong stability and Long service life; as the base of the master plate, it can be reused, and can be easily released from the UV-cured resin after surface treatment, with good consistency; the 3D jet printing technology used belongs to the additive preparation technology, and the material utilization rate is high , which greatly reduces the cost; while using transfer imprinting, the requirements for imprinting equipment are lower. Even if no imprinting force is applied, the resin on the substrate and the master can be naturally adhered to each other by relying on the natural flow of the resin. Relatively simple. Even better, micro-contact transfer imprinting is even better.

More preferably, in another embodiment: the additional substrate can be a rigid substrate such as quartz, a silicon wafer, or a flexible substrate such as PET plastic, PDMS, etc., depending on its application field. That is, this embodiment is applicable to both rigid and flexible substrates.

More preferably, in another embodiment: the characteristic size of the microstructure is submicron, the resin is filled into the microstructure, and an initial micro-nano composite structure is formed on the master.

For this embodiment, the micron-scale and sub-micron-scale structures in this field can be transferred to the UV-curable adhesive at one time, and the two-stage structure is the same material, which has strong stability and long service life ;As the master plate, the substrate with sub-micron structure can be reused. After surface treatment, it can be easily released from the UV-cured resin, and the consistency is good; The speed of graphics; after 3D jet printing, the droplets on the master plate naturally form a microlens structure with a spherical shape due to surface tension. After transfer printing, the micron-scale structure on the substrate is inverted spherical, and a special-shaped bionic sub-micron-scale structure can be obtained.

More preferably, in another embodiment: in step (b), by adjusting the jet printing parameters, including but not limited to the number of jet printing, droplet volume, to change the diameter and height of the microlens, and then change the micro-nano composite structure shape. Apparently, this embodiment provides a way to change the micro-nano composite structure through jet printing parameters.

More preferably, in another embodiment: in step (d), utilize similar and compatible principle, resin microlens is in contact with the resin that is spin-coated on the base that step (c) gains, through applying certain pressure and curing step , the two have a strong bonding force, and the resin on the master plate is transferred to the substrate after demoulding. As far as this embodiment is concerned, it discloses a technical solution of how to contact and transfer.

More preferably, in another embodiment: for the resin transferred to the substrate, the bottom side of the resin originally filled inside the microstructure of the master plate becomes the top of the resin on the substrate after transfer imprinting, and has The submicron-scale structure that is the opposite of the structure on the master; correspondingly, the top of the microlens becomes the bottom of the resin on the substrate. As far as this embodiment is concerned, the liquid droplets on the master plate after 3D jet printing naturally form a microlens structure with a spherical shape due to surface tension, and the micron-scale structure on the substrate after transfer printing is inverted spherical, and special-shaped bionic submicron-scale structures can be obtained. If the structure is further combined with the submicron-scale structure at the top, then this composite structure obviously has better adhesion and a wider range of adhesion angles than the straight-up and straight-down topography.

Below in conjunction with accompanying drawing and other embodiments the present invention is described in further detail:

(1) As shown in accompanying drawing 1a, spin-coat a layer of electron beam glue 12 on the transparent quartz substrate 11, and carry out pre-baking, the pre-baking temperature is 90 ℃, and the time is 5 min;

(2) As shown in accompanying drawing 1b, patterned electron beam glue 13 by electron beam exposure process, ultraviolet exposure time is 10s, developing solution is electron beam glue developing solution, and developing time is 30s, and post-baking, post-baking temperature at 95°C for 10 minutes;

(3) As shown in accompanying drawing 1c, the photoresist after exposure and development is used as a mask, and the microstructure is prepared on the quartz substrate by reactive ion etching technology. and 15 sccm. The aspect ratio of the quartz surface microstructure can be adjusted by changing the etching time and etching power;

(4) As shown in accompanying drawing 1d, wash away the residual electron beam glue mask with NaOH solution of appropriate concentration;

(5) As shown in Figure 2a, a fluorosilane hydrophobic layer 22 is prepared on a silicon substrate 21 with a microstructure, the purpose of which is to reduce the surface energy of the silicon master and facilitate the subsequent demoulding process;

(6) As shown in accompanying drawing 2b, the resin microlens array 23 is further prepared on a silicon substrate with a submicron-scale structure and surface hydrophobic treatment by jet printing and is cured by ultraviolet light. The curing time is 5 minutes, and the microlens The arrangement and duty cycle of the array can be designed according to the needs;

(7) As shown in FIG. 3 a , spin-coat the UV-curable resin 32 on the substrate 31 to be subjected to contact imprinting, for example, with a thickness of 1 micron. The resin is the same material as the resin used to prepare the microlens array, so as to ensure better bonding strength. In this step, the resin 32 is not cured first. The substrate 31 in this step can be a rigid substrate such as quartz or a silicon wafer, or a flexible substrate such as PET plastic or PDMS, depending on its application field.

(8) Next, as shown in accompanying drawing 3b, substrate 21 and substrate 31 in Fig. 3a are subjected to contact embossing, applying 10N embossing, embossing time is 5 minutes, and then UV curable resin 32 is imprinted in embossing process UV curing was carried out for 5 minutes.

(9) As shown in FIG. 3 c , a demolding step is performed, and the microlens array on the quartz substrate 21 and the microstructures on the quartz substrate 21 are all transferred to the substrate 31 after the demoulding is completed.

Fig. 4 is a scanning electron micrograph of a micro-nano composite structure prepared by transfer imprinting on a quartz substrate according to an embodiment of the present invention.

The principles and implementation methods of the present disclosure have been described above using specific examples. The descriptions of the above embodiments are only used to help understand the technical solutions and core ideas of the present disclosure; for those skilled in the art, according to the ideas of the present disclosure, specific There will be changes in the implementation and scope of application. To sum up, the contents of this specification should not be construed as limiting the present disclosure.

Claims (5)

1. A manufacturing process of a bionic special-shaped micro-nano composite structure based on 3D jet printing technology, comprising the following steps: (a) master patterning step, preparing microstructures on the single crystal silicon master by photolithography and deep dry etching process; (b) a jet printing step, first performing a low surface energy treatment on the patterned substrate in step (a), then depositing a resin microlens array on the substrate through a jet printing process, and performing ultraviolet curing; (c) Prepare the substrate step, coat the UV-curable resin on another substrate, select the same resin material as in step (b); (d) transfer embossing step, the substrate obtained in step (c) is docked with the master plate treated in step (b) and transferred and imprinted, a certain pressure is applied, ultraviolet curing is carried out, and then the mold is demoulded, and the final master plate The resin material is transferred to the substrate. 2. The manufacturing process according to claim 1, characterized in that: preferably, the characteristic size of the microstructure is sub-micron, the resin is filled into the microstructure, and the initial micro-nano composite structure is formed on the master plate . 3. The manufacturing process as claimed in claim 1, characterized in that: in step (b), by adjusting the jet printing parameters, including but not limited to the number of jet printing, droplet volume, to change the diameter and height of the microlens, and then Change the morphology of the micro-nano composite structure. 4. The manufacturing process as claimed in claim 2, characterized in that: in step (d), using the principle of similar compatibility, the resin microlens is in contact with the resin that is spin-coated on the substrate obtained in step (c), and after applying Certain pressure and curing steps, the two have a strong bonding force, and the resin on the master plate is transferred to the substrate after demoulding. 5. The manufacturing process as claimed in claim 4, characterized in that: for the resin transferred to the substrate, the bottom side of the resin originally filled in the microstructure of the master plate becomes the resin on the substrate after transfer imprinting The top of the microlens has a submicron-scale structure opposite to the structure on the master; correspondingly, the top of the microlens becomes the bottom of the resin on the substrate.