Concentration Device

A concentration device includes a substrate that has a flow path formed therein extending from an inlet-side opening into which a liquid to be concentrated is introduced to an outlet-side opening, and a desiccant that is disposed in containing spaces in the substrate to face a liquid in the flow path across air layers.

TECHNICAL FIELD

The present invention relates to a concentration device that concentrates a liquid.

BACKGROUND

Sweating sensors have recently attracted attention because they can detect components such as electrolyte ions, alcohols, glucose, urea, lactic acid, proteins, and hormones contained in body fluids without invasive procedures such as blood tests. Non-Patent Literature 1 discloses a wearable sensor capable of monitoring components of sweat.

Of such components of sweat, sodium and chloride ions are reabsorbed in sweat glands in the process of sweating, and their concentrations in sweat are thus lower than those in blood. Other components of sweat than the sodium and chloride ions are in trace amounts, and need a highly sensitive sensor to be detected (see Non-Patent Literature 2).

CITATION LIST

SUMMARY

Technical Problem

Embodiments of the present invention have been made to solve the above-mentioned problem, and it is an object of embodiments of the present invention to provide a concentration device capable of concentrating a liquid.

Means for Solving the Problem

A concentration device of embodiments of the present invention includes a substrate that has a first flow path formed therein extending from an inlet-side opening into which a liquid to be concentrated is introduced to an outlet-side opening, and a desiccant that is disposed in containing spaces in the substrate to face a liquid in the first flow path across air layers.

Effects of embodiments of the Invention

According to embodiments of the present invention, the desiccant adsorbs a solvent vapor generated through evaporation of a liquid containing a non-volatile solute, and the liquid can thereby be concentrated. For example, the use of the concentration device of embodiments of the present invention for detecting components of sweat allows detection sensitivity to the components contained in sweat to be improved, and thus analysis of the components can be achieved without a highly sensitive sensor.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.FIG.1is an outline view of a concentration device according to the embodiment of the present invention, andFIG.2is a front view of a flow path member constituting the concentration device. A concentration device1of the present embodiment includes a substrate2that has a flow path5formed therein extending from an inlet-side opening3into which a liquid to be concentrated is introduced to an outlet-side opening4, and a desiccant6that is disposed in containing spaces7in the substrate2to face a liquid in the flow path5across air layers.

The substrate2consists of a plate-shaped flow path member2aand a plate-shaped lid member2bjoined to the flow path member2a.

FIG.3is an enlarged view of the part A inFIG.2, andFIG.4is a cross-sectional view of the concentration device1with the flow path member2abeing joined to the lid member2b.

In the flow path member2a,there are formed the flow path5in a grooved shape, the containing spaces7in a grooved shape that are formed on the opposite sides of the flow path5and contain the desiccant6, and a plurality of flow paths fin a grooved shape that allow communication between the flow path5and the containing spaces7. The flow paths8are formed in the side wall of the flow path5separating the flow path5and the containing spaces7.

As a result, the desiccant6faces the liquid in the flow path5across the air layers in the flow paths8.

In the lid member2b,a through hole9is formed to cut through the lid member2bfrom the front surface to the back surface in a position such that the through hole9communicates with the inlet-side end of the flow path5when the flow path member2ais joined to the lid member2b.The opening on the front surface side of the through hole9serves as the inlet-side opening3of the concentration device1.

In the lid member2b,a through hole10is also formed to cut through the lid member2bfrom the front surface to the back surface in a position such that the through hole10communicates with the outlet-side end of the flow path5when the flow path member2ais joined to the lid member2b.The opening on the front surface side of the through hole10serves as the outlet-side opening4of the concentration device1.

In the lid member2b,vents11are further formed to cut through the lid member2bfrom the front surface to the back surface in positions such that the vents11communicate with the containing spaces7when the flow path member2ais joined to the lid member2b.The reason for forming the vents11is that providing the vents11causes the air in the containing spaces7to be discharged to decrease the vapor pressure and to facilitate movement of the vapor from the flow path5to the desiccant6in the containing spaces7.

Examples of materials available for the flow path member2aand the lid member2binclude synthetic resins having high water repellence such as polydimethylsiloxanes, cycloolefin polymers, acrylic resins, and polycarbonates. For the flow path member2aand the lid member2b,a processed material is also available which has been subjected to a surface treatment for providing water repellence or a coating process for forming a water repellent film onto the surface of any hydrophilic material, the inner surface of the flow path5, and the inner surfaces of the through holes9to10.

As described above, the desiccant6is contained in the grooved containing spaces7formed on the opposite sides of the flow path5in the flow path member2a.Examples of the desiccant6include water vapor adsorbents such as silica gel, activated alumina, and zeolite.

The flow path member2aand the lid member2bare joined to each other so that, with the desiccant6contained in the containing spaces7, the inlet-side end of the flow path5communicates with the through hole9, the outlet-side end of the flow path5communicates with the through hole10, the containing spaces7communicate with the vents11, and the lids of the flow paths5,8are closed. Examples of joining methods include direct joining, adhesive joining, and mechanical joining, but the present invention is not limited to these joining methods.

The flow path member2aand the lid member2bmay also be integrally formed using a 3D printer, for example.

FIG.5illustrates a state in which a liquid100to be concentrated is introduced into the flow path5through the inlet-side opening3and flows in the flow path5.

To facilitate movement of the liquid100, the concentration device1is desirably installed so that the inlet-side opening3is located above the outlet-side opening4and the flow path5is disposed vertically downward or obliquely downward. When the flow path5is disposed horizontally, the liquid100is desirably fed with a pump.

Because the vapor pressure in the containing spaces7is lower than that in the flow path5, the vapor generated through evaporation of the liquid100moves toward the containing spaces7through the flow paths8and is adsorbed by the desiccant6in the containing spaces7.

In this way, the desiccant6adsorbs the solvent vapor generated through evaporation of the liquid100containing a non-volatile solute, and the liquid100is thereby concentrated and the concentrated liquid100can be discharged from the outlet-side opening4to the outside.

Although the liquid wo unlikely enters the flow paths8because of the water repellence of the flow path member2a,the opening area and length of the flow paths8are desirably determined such that the liquid wo is not allowed to pass through the flow paths8and the vapor is allowed to pass through the flow paths8. The concentration rate of the liquid wo can be adjusted by changing the opening rate of the side wall of the flow path5(the ratio of the opening area of the flow paths8to the total area of the side wall when the flow paths8are not provided in the side wall).

As an exemplary usage of the concentration device1of the present embodiment, sweat collected from skin of a subject is introduced into the concentration device1and components contained in the concentrated sweat may be detected. A method for detecting concentrations of such components is disclosed in Non-Patent Literature 1. The use of the concentration device1of the present embodiment allows detection sensitivity to the components contained in sweat to be improved, and thus analysis of the components can be achieved without a highly sensitive sensor.

The concentration device1of the present embodiment is available not only to sweat but also to aqueous solutions in general.

INDUSTRIAL APPLICABILITY

Embodiments of the present invention are available to techniques for concentrating a liquid.

REFERENCE SIGNS LIST

2aflow path member