CN107879309B

CN107879309B - Hollow Cantilever Probe for Micro-Nano-Scale Substance Delivery and Extraction

Info

Publication number: CN107879309B
Application number: CN201711111195.7A
Authority: CN
Inventors: 宋杰; 齐岱宗
Original assignee: Shanghai Jiao Tong University
Current assignee: Shanghai Jiao Tong University
Priority date: 2017-11-13
Filing date: 2017-11-13
Publication date: 2020-05-05
Anticipated expiration: 2037-11-13
Also published as: CN107879309A

Abstract

A hollow cantilever probe for the delivery and extraction of micro-nano-scale substances, the hollow cantilever probe is a flat cube structure, and is composed of a funnel-shaped probe and a tubular cantilever beam, wherein: the cantilever beam and the probe are hollow inside And they are connected to transport substances, that is, with one end of the cantilever beam as the start end and the open end of the probe tip as the end, by applying positive or negative pressure at the beginning end, the substance is sucked or delivered from the end to the surface of the sample. The present invention uses MEMS technology to properly transform the traditional cantilever beam and the probe, and can obtain a new structure with the functions of material delivery and extraction, that is, the combined structure of the cantilever beam and the probe with the transport channel "hollow cantilever probe"". The invention reflects the surface topography information of the sample by attracting or repelling the surface of the sample.

Description

Hollow cantilever probe for delivering and extracting micro-nano scale substances

Technical Field

The invention relates to a technology in the micro-nano field, in particular to a hollow cantilever probe for delivering and extracting micro-nano scale substances, which realizes the delivery and extraction of the micro-nano scale substances.

Background

An Atomic Force Microscope (AFM) is used as an analytical instrument for the surface structure of an object, and realizes the observation of the surface appearance and properties of a sample by means of the Atomic-level interaction between a miniature Force-sensitive element and the surface of the sample and the conversion of the miniature Force-sensitive element into an electric signal which can be detected and processed by a sensor; the resolution ratio can be refined to nanometer level, a three-dimensional surface map can be provided, and the method does not require a vacuum experimental environment or special treatment on a sample, and is widely applied to the industrial and research fields of biotechnology, conversion medicine and the like. The core part of the atomic force microscope is the cantilever and the probe which are used as force-sensitive elements, and the part also determines the use performance and the specific working mode of the whole machine.

A Micro Electro Mechanical System (MEMS) is a combination of a Micro electronic technology and a Micro processing technology, and a Mechanical structure is manufactured and processed on a Micro-nano scale; the mature bulk micromachining technology can selectively remove the substrate by corrosive agents and obtain the micromechanical element with specific appearance, and is an ideal process for manufacturing the cantilever and the probe part of the atomic force microscope from the facing dimension and the applicable materials.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the hollow cantilever probe for delivering and extracting the micro-nano scale substances, and the traditional cantilever beam and the probe are properly modified by the MEMS technology, so that a new structure with the functions of delivering and extracting the substances can be obtained, namely a combined structure of the cantilever beam with a conveying channel and the probe, namely the hollow cantilever probe. The invention reflects the surface appearance information of the sample by attracting or repelling the surface of the sample, and the observation is carried out in short; the device is used for realizing the delivery and extraction of substances with corresponding scales on the basis of the observation function of the existing atomic force microscope.

The invention is realized by the following technical scheme:

the invention relates to a method for preparing a hollow cantilever probe, which comprises the steps of obtaining a quadrangular pyramid-shaped concave hole with a cantilever beam on the surface of a substrate through anisotropic etching, then placing a covering layer above the concave hole, carrying out low-temperature oxidation deposition, finally removing the redundant substrate at the bottom of the concave hole and eliminating the hole opening of the concave hole and the other end of the cantilever beam through a photoetching process to obtain the hollow cantilever probe.

The anisotropic etching specifically comprises the following steps: the cantilever profile of a conventional probe is etched away on the substrate surface by a Reactive Ion Etching (RIE) process, and a quadrangular pyramid-shaped cavity is created near one end of the profile by anisotropic etching with KOH.

The distance between the lower surface of the covering layer and the upper surface of the substrate is not in contact with each other, and the closest distance is 1 micron.

The covering layer is made of, but not limited to, silicon wafer.

The substrate is a silicon wafer but not limited to.

The removal is not limited to the use of halogen gas (F)₂Or Cl₂Gas) to remove excess substrate.

The invention relates to a hollow cantilever probe prepared by the method, which is of a flat cubic structure and consists of a funnel-shaped probe and a tubular cantilever beam, wherein: the cantilever beam is hollow and communicated with the interior of the probe to convey substances.

The length of the partial side of the middle beam of the hollow cantilever probe is 80-10 mu m long x-10 mu m wide x-2 mu m thick, the length and width difference between the inner diameter and the outer diameter can be ignored on the whole scale, the thickness of the cavity is about 1 mu m, and the caliber of the needle tip is 500 nm.

The invention relates to the application of the hollow cantilever probe prepared by the method, which takes one end of a cantilever beam as a starting end and one end of a needle point opening of the probe as a tail end, and realizes the suction or delivery of a substance from the tail end to the surface of a sample by applying positive pressure or negative pressure to the starting end.

Technical effects

Compared with the prior art, the invention realizes the substance transfer equivalent to the structure scale, so that the delivery and the extraction can be carried out on the molecular or molecular group level, and the operation on the cell and sub-cell level can be carried out on the biological tissue according to the research requirement. The optimized design and improved manufacture of the cantilever beam and the probe expand the capability range of related research and provide basis and possibility for system research with larger view.

Drawings

FIG. 1 is a schematic view of the process of the present invention;

in the figure: a to f are corresponding working procedures of the invention;

FIG. 2 is a schematic diagram illustrating the effects of the embodiment.

Detailed Description

The embodiment comprises the following steps:

1) etching the cantilever beam profile of the traditional probe on the surface of a silicon wafer by a Reactive Ion Etching (RIE) process, and generating a quadrangular pyramid-shaped concave hole near one end of the profile by utilizing the anisotropic etching of KOH;

2) another silicon chip is taken to be covered upside down, and the surface distance between the two silicon chips is controlled to be about 1 micron;

3) forming an oxidation growth layer on the surface of the silicon wafer by a gate oxidation process, wherein the edge of the cantilever beam reverse mould profile is also connected with the oxide layer grown on the top silicon wafer in the process;

the gate oxidation process specifically comprises the following steps:

3.1) pre-cleaning: o is₂Maintaining the temperature of an oxidation furnace chamber in the atmosphere of HCl mixed gas at 1100 ℃ for 1 hour, and then maintaining the temperature with N₂Purging and cooling to 800 ℃;

3.2) loading: at O₂And N₂Loading the sample into an oxidation furnace chamber in the mixed gas atmosphere;

3.3) oxidizing: at O₂Oxidizing with HCl at 1000 deg.C to grow SiO₂；

3.4) annealing: in N₂Annealing at 1050 ℃ in a gas atmosphere;

3.5) cooling: stopping heating and heat preservation, and taking out the sample when the temperature in the cavity is reduced to be below 800 ℃.

4) With halogen gas (F)₂Gas or Cl₂Gas) to remove the silicon substrate;

5) the tip and the tail of the cantilever are removed by photolithography to obtain a hollow cantilever probe.

The photoetching process specifically comprises the following steps:

5.1) gluing: positive glue;

5.2) prebaking: hot plate at 80 ℃ for 4 hours;

5.3) exposure: 2 hours and 30 minutes;

5.4) developing: 3 minutes;

5.5) post-baking: oven at 90 deg.C for 5 hr;

5.6) etching;

5.7) removing the photoresist.

As shown in FIG. 2, the cantilever probe prepared in this example is a flat cubic structure, wherein the side length of the beam is-80 μm long x-10 μm wide x-2 μm thick, the difference between the inner diameter and the outer diameter is negligible in the whole dimension, the thickness of the cavity is about 1 μm, and the caliber of the tip is-500 nm; the funnel-shaped probe and the tubular cantilever beam jointly form a new cantilever probe, and the hollow structure of the new cantilever probe can meet the requirement of material conveying. The opening of the cantilever of the hollow cantilever probe is used as a starting end, the opening of the needle point of the probe is used as a tail end, liquid or gas which has certain pressure and does not react with the material is injected into the starting end, and the material on the surface of the sample near the tail end can be sucked or the material in the cavity can be delivered to the surface of the sample through the tail end by controlling the pressure.

The foregoing embodiments may be modified in many different ways by those skilled in the art without departing from the spirit and scope of the invention, which is defined by the appended claims and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. a preparation method of a hollow cantilever probe, is characterized in that, by obtaining the quadrangular pyramid concave cavity with cantilever beam by anisotropic corrosion on the substrate surface, then a covering layer is placed above the concave cavity and low temperature is carried out. Oxidative deposition, finally removing the excess substrate at the bottom of the cavity and removing the cavity opening and the other end of the cantilever beam with a photolithography process to obtain a hollow cantilever probe with a flat cube structure. The hollow cantilever probe consists of a funnel-shaped probe and a tubular It is composed of a cantilever beam, wherein: the cantilever beam and the probe are hollow and connected to transport substances;

The lower surface of the cover layer is not in contact with the upper surface of the substrate and the closest distance is 1 micron.

2. The method according to claim 1, wherein the method specifically comprises:

1) The cantilever beam profile is etched on the surface of the silicon wafer as the substrate by a reactive ion etching process, and a quadrangular pyramid-shaped concave is generated at one end of the cantilever beam profile by anisotropic etching of KOH;

2) another silicon wafer is taken as the cover layer and overlaid on it, and the surface spacing of the lower surface of the control cover layer and the upper surface of the substrate is 1 micrometer;

3) An oxide growth layer is formed on the surface of the silicon wafer as the substrate with the gate oxidation process, and the edge of the cantilever beam inversion profile during this process will also be connected with the silicon wafer positioned above as the cover layer with the grown oxide layer;

4) removing the substrate with halogen gas;

5) Remove the tip of the needle and the tail of the cantilever beam by a photolithography process to obtain a hollow cantilever probe.