# US 2018/0021777 A1 · Fluid testing chip and cassette

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- Number: US 2018/0021777 A1
- Document ID: US20180021777A1
- Status: Published application
- Kind: A1
- Application number: 15/546,742
- Filed: 2015-01-30
- Published: 2018-01-25
- Earliest claimed: 2015-01-30
- Assignees: Hewlett-Packard Development Company, L.P.
- Applicants: Hewlett-Packard Development Company, L.P.
- Inventors: Manish Giri; Chantelle E. Domingue; Robert J. Moline
- Web page: https://patentgrep.com/patent/US20180021777A1

## CPC

- B01L 3/502715: {characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces}
- B01L 3/502761: {specially adapted for handling suspended solids or molecules independently from the bulk fluid flow, e.g. for trapping or sorting beads or physically stretching molecules}
- G01N 15/0266: {with electrical classification}
- G01N 15/1023: {Microstructural devices for non-optical measurement}
- G01N 15/1031: by measuring electrical or magnetic effects
- G01N 33/86: involving blood coagulating time {or factors, or their receptors}
- B01L 2200/0647: Handling flowable solids, e.g. microscopic beads, cells, particles
- B01L 2200/10: Integrating sample preparation and analysis in single entity, e.g. lab-on-a-chip concept
- B01L 2300/044: pierceable, e.g. films, membranes
- B01L 2300/0627: Sensor or part of a sensor is integrated
- B01L 2300/0645: Electrodes
- B01L 2300/0681: Filter
- B01L 2300/0816: Cards, e.g. flat sample carriers usually with flow in two horizontal directions
- B01L 2300/0867: Multiple inlets and one sample wells, e.g. mixing, dilution
- B01L 2300/088: Channel loops
- B01L 2300/0883: Serpentine channels
- B01L 2400/0406: capillary forces
- B01L 2400/0439: ultrasonic vibrations, vibrating piezo elements
- B01L 2400/0442: thermal energy, e.g. vaporisation, bubble jet
- B01L 2400/086: using baffles or other fixed flow obstructions
- G01N 15/01: specially adapted for biological cells, e.g. blood cells (investigating sedimentation of particle suspensions in blood G01N15/05)
- B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- 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 fluid testing cassette may comprise a microfluidic channel extending having a constriction and a micro-fabricated integrated sensor within the constriction. In one implementation, the constriction is less than or equal to 30 μm. In one implementation, the cassette further comprises a nozzle connecting the microfluidic channel to the discharge reservoir, wherein a thermal resistor expels fluid within the microfluidic channel into the discharge reservoir.

## Claims

### Claim 1

A fluid testing cassette comprising:
a chip comprising:
a microfluidic reservoir;
a microfluidic channel extending from the microfluidic reservoir and having a constriction having a width of no greater than 30 μm; and
a micro-fabricated integrated sensor within the constriction.

### Claim 2 (depends on 1)

The fluid testing cassette of claim 1 further comprising a cassette body supporting the chip, the cassette body comprising a sample input port connected to the microfluidic reservoir.

### Claim 3 (depends on 2)

The fluid testing cassette of claim 2 further comprising:
a reagent within the sample input port; and
a membrane across a mouth of the sample input port sealing the reagent within the sample input port.

### Claim 4 (depends on 2)

The fluid testing cassette of claim 2 further comprising:
a reagent within the sample input port; and
a removable packaging completely enclosing the cassette body and the chip.

### Claim 5 (depends on 2)

The fluid testing cassette of claim 2 further comprising a residence passage tortuously extending from the sample input port to microfluidic reservoir.

### Claim 6 (depends on 5)

The fluid testing cassette of claim 5, wherein the residence passage has upstream portions proximate the sample input port and downstream portions proximate the chip, wherein the upstream portions are vertically below the downstream portions such that fluid flowing from the upstream portions to the downstream portions flows against gravity.

### Claim 7 (depends on 2)

The fluid testing cassette of claim 2, wherein the cassette body further comprises a discharge reservoir to receive fluid that has passed through the chip.

### Claim 8 (depends on 7)

The fluid testing cassette of claim 7, wherein the chip further comprises:
a nozzle connecting the microfluidic channel to the discharge reservoir; and
a thermal resistor to expel fluid through the nozzle into the discharge reservoir.

### Claim 9 (depends on 1)

The fluid testing cassette of claim 1, wherein the microfluidic channel comprises:
a first portion extending from the microfluidic reservoir and containing a thermal resistor;
a second portion branching from the first portion back to the microfluidic reservoir, the second portion having the constriction containing the impedance sensor; and
a third portion branching from one of the first portion and the second portion back to the microfluidic reservoir, the second portion having a second constriction containing a second impedance sensor.

### Claim 10 (depends on 9)

The fluid testing cassette of claim 9, wherein the first portion has an inlet from the reservoir of a first width, wherein the second portion has an outlet to the reservoir of a second width greater than the first width and wherein the third portion has an outlet to the reservoir of a third width greater than the first width.

### Claim 11 (depends on 1)

The fluid testing cassette of claim 1, wherein the microfluidic channel comprises a second constriction containing a second sensor, wherein the constriction has a first width and wherein the second constriction has a second width different than the first width.

### Claim 12 (depends on 1)

The fluid testing cassette of claim 1 further comprising a thermal resistor within the microfluidic channel to pump fluid through the microfluidic channel, wherein the thermal resistor has a length along the microfluidic channel, wherein the sensor is spaced from the thermal resistor along the microfluidic channel by a spacing of at least the length.

### Claim 13 (depends on 1)

The fluid testing cassette of claim 1 further comprising a thermal resistor within the microfluidic channel to pump fluid through the microfluidic channel, wherein the thermal resistor has a length along the microfluidic channel, wherein the thermal resistor is spaced from the microfluidic reservoir along the microfluidic channel by a spacing of at least the length.

### Claim 14 (depends on 1)

The fluid testing cassette of claim 1, wherein the sensor has a length along the microfluidic channel, wherein the microfluidic channel has a second constriction, wherein the chip further comprises a second micro-fabricated integrated sensor within the second constriction and wherein the second micro-fabricated integrated sensor is spaced from the sensor by a distance of at least twice the length.

### Claim 15

A fluid testing cassette comprising:
a microfluidic channel having a constriction;
a micro-fabricated integrated sensor within the constriction;
a discharge reservoir;
a nozzle connecting the microfluidic channel to the discharge reservoir
a thermal resistor within the microfluidic channel to expel fluid in the microfluidic channel into the discharge reservoir.