# US 2008/0185515 A1 · Polymer based electrospray nozzle for mass spectrometry

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2008/0185515 A1
- Document ID: US20080185515A1
- Status: Published application
- Kind: A1
- Application number: 11/942,647
- Filed: 2007-11-19
- Published: 2008-08-07
- Earliest claimed: 1998-11-19
- Assignees: California Institute of Technology
- Inventors: Yu-Chong TAI; Xuan-Qi WANG; Amish DESAI; Terry D. LEE; Lawrence Licklider
- Web page: https://patentgrep.com/patent/US20080185515A1

## CPC

- H01J 49/167: {Capillaries and nozzles specially adapted therefor; (electrostatic spraying per se B05B5/00)}
- G01N 30/6095: {Micromachined or nanomachined, e.g. micro- or nanosize}
- G01N 30/7266: {by electric field, e.g. electrospray}
- H01J 49/0018: {Microminiaturised spectrometers, e.g. chip-integrated devices, Micro-Electro-Mechanical Systems [MEMS]}
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

A MEMS device with an overhanging ‘polymer’ capillary provides vital and significant improvements in interfacing a MEMS electrospray nozzle to an MS inlet or other macroscopic instrumentation. The fabrication methodology associated therewith is easily expanded to include built-in micro particle filters and centimeter long serpentine micro channels provided on-chip and fabricated using a low temperature process.

## Claims

### Claim 1

A method of fabricating a polymer-based micromachined electrospray nozzle structure, comprising:
obtaining a support substrate;
first forming a first polymer layer on said support substrate which will form a floor of said nozzle structure;
first patterning said first layer to form a first inlet window;
second forming an interior layer over said first layer;
second patterning a portion of said interior layer to form a filtered channel field, said filtered channel field forming a path through which fluid can flow;
third forming a second polymer layer, said second layer forming a roof of said polymer-based nozzle structure; and
first etching said support substrate to expose a nozzle tip and releasing said first inlet window.

### Claim 2 (depends on 1)

A method as in claim 1, wherein said support substrate is silicon.

### Claim 3 (depends on 1)

A method as in claim 1, wherein said first and second polymer layers are Parylene layers.

### Claim 4 (depends on 1)

A method as in claim 1, wherein said interior layer is a photoresist layer.

### Claim 5 (depends on 1)

A method as in claim 1, wherein said filtered channel field comprises filter elements disposed around the first inlet window.

### Claim 6 (depends on 5)

A method as in claim 5, wherein said filtered channel field further comprises serpentine channels disposed downstream, relative to the flow of fluid, from the first inlet window.

### Claim 7 (depends on 6)

A method as in claim 6, wherein said step of first patterning said first layer to form a first inlet window, also forms a second inlet window.

### Claim 8 (depends on 1)

A method as in claim 1, wherein said filtered channel field comprises serpentine channels disposed downstream, relative to the flow of fluid, from the first inlet window.

### Claim 9 (depends on 1)

A method as in claim 1, wherein said step of first patterning said first layer to form a first inlet window, also forms a second inlet window.

### Claim 10 (depends on 1)

A method as in claim 1, wherein prior to said first forming a first polymer layer on said support substrate, gas phase etching a surface of the support substrate.

### Claim 11 (depends on 10)

A method as in claim 10, wherein said gas phase etching is done with bromine trifluoride (BF3).

### Claim 12 (depends on 1)

A method as in claim 1, wherein said polymer-based nozzle structure is a MEMS device adapted for coupling to an inlet of a mass spectrometer using electrospray ionization (ESI).

### Claim 13

A micromachined polymer-based apparatus, comprising:
a support substrate;
a nozzle structure formed on said support substrate and defined by at least a first and second polymer layers and an interior layer; and
a first inlet window formed on said nozzle structure and adapted for receiving, from a capillary tube, a sample into said nozzle structure via said first inlet window.

### Claim 14 (depends on 13)

An apparatus as in claim 13, wherein said first and second polymer layers are Parylene layers.

### Claim 15 (depends on 13)

An apparatus as in claim 13, wherein said interior layer is a photoresist layer.

### Claim 16 (depends on 13)

An apparatus as in claim 13, wherein said interior layer defines a filtered channel field comprising filter elements disposed around the first inlet window.

### Claim 17 (depends on 16)

An apparatus as in claim 16, wherein said filtered channel field further comprises serpentine channels disposed downstream, relative to the flow of fluid, from the first inlet window.

### Claim 18 (depends on 17)

An apparatus as in claim 17, further comprising a second inlet window formed on said nozzle structure and adapted for receiving, from a different capillary tube, a sample into said nozzle structure via said second inlet window.

### Claim 19 (depends on 13)

An apparatus as in claim 13, wherein said interior layer defines a filtered channel field comprising serpentine channels disposed downstream, relative to the flow of fluid, from the first inlet window.

### Claim 20 (depends on 13)

An apparatus as in claim 13, wherein said nozzle structure is a MEMS device adapted for coupling to an inlet of a mass spectrometer using electrospray ionization (ESI).