Rapid delivery and/or receiving of fluids

Abstract

The present invention generally relates to systems and methods for delivering and/or receiving a substance or substances such as blood, from subjects, e.g., from the skin and/or from beneath the skin. In one aspect, the present invention is generally directed to devices and methods for receiving or extracting blood from a subject, e.g., from the skin and/or from beneath the skin, using devices containing a fluid transporter (for example, one or more microneedles), and a storage chamber having an internal pressure less than atmospheric pressure prior to receiving blood. In some cases, the device may be self-contained, and in certain instances, the device can be applied to the skin, and activated to receive blood from the subject. The device, or a portion thereof, may then be processed to determine the blood and/or an analyte within the blood, alone or with an external apparatus. For example, blood may be received from the device, and/or the device may contain sensors or agents able to determine the blood and/or an analyte suspected of being contained in the blood. In another aspect, the present invention is generally directed to arrangements of skin insertion objects such as microneedles and methods of forming and arranging skin insertion objects. Other aspects of the present invention are directed at other devices for receiving blood (or other bodily fluids, e.g., interstitial fluid), kits involving such devices, methods of making such devices, methods of using such devices, and the like.

What is claimed is: 
     
         1 . A microneedle structure comprising:
 a first plurality of microneedles that each include a base portion and a penetrating portion, the base portions of the first plurality of microneedles being arranged at the periphery of a first closed loop lying in a plane, the penetrating portions of the first plurality of microneedles each extending at a respective angle away from the plane of the first closed loop; and   a second plurality of microneedles that each include a base portion and a penetrating portion, the base portions of the second plurality of microneedles being arranged at a periphery of a second closed loop lying in the plane, the second closed loop being larger than, and surrounding, the first closed loop, the penetrating portions of the second plurality of microneedles each extending at a respective angle away from the plane of the second closed loop.   
     
     
         2 . The structure of  claim 1 , wherein the first closed loop is a circle, and the penetrating portions extend perpendicularly away from the plane. 
     
     
         3 . The structure of  claim 1 , wherein the first and second closed loops are concentric circles. 
     
     
         4 . The structure of  claim 1 , wherein the first closed loop has a circular, elliptical, hexagonal, rectangular, pentagonal, octagonal or irregular shape. 
     
     
         5 . The structure of  claim 1 , wherein a packing density of the microneedles is at least 2 microneedles per square millimeter. 
     
     
         6 . (canceled) 
     
     
         7 . The structure of  claim 1 , wherein the penetrating portion is arranged to pierce human skin and extend at least 100 microns into the skin. 
     
     
         8 - 10 . (canceled) 
     
     
         11 . The structure of  claim 1 , wherein the microneedles have a combined skin-penetration area of at least about 500 square nanometers. 
     
     
         12 - 14 . (canceled) 
     
     
         15 . The structure of  claim 1 , wherein each penetrating portion includes a proximal portion that is formed integral with the base portion and a distal portion having a point that is formed at an intersection of at least four surfaces of the penetrating portion; 
     
     
         16 . The structure of  claim 1 , wherein each penetrating portion includes a proximal portion that is formed integral with the base portion and a distal portion, the distal portion having an approximately hexagon-shaped cross section. 
     
     
         17 . The structure of  claim 1 , wherein each penetrating portion has a sword shape with a symmetrical V-type knife edge at a periphery of the penetrating portion. 
     
     
         18 . The structure of  claim 1 , wherein at least some of the microneedles are coated with a substance. 
     
     
         19 . The structure of  claim 18 , wherein the substance comprises one or more of lidocaine, bupivacaine, and tetracaine. 
     
     
         20 . A device comprising a plurality of the structures recited in  claim 1 . 
     
     
         21 . The structure of  claim 1 , wherein the base portions of the first and second pluralities of microneedles are connected together. 
     
     
         22 . (canceled) 
     
     
         23 . A method for forming a microneedle structure, comprising:
 providing a layer of material having opposed substantially planar sides;   etching the layer of material to define a plurality of microneedles such that bases of the microneedles are arranged at a periphery of a first closed loop and each of the microneedles extends toward a center of the first closed loop; and   etching the layer of material to define a second plurality of microneedles with bases arranged at a periphery of a second closed loop that is arranged around the first closed loop.   
     
     
         24 . The method of  claim 23 , wherein the first closed loop has a substantially circular, elliptical, hexagonal, rectangular, pentagonal, octagonal or irregular shape. 
     
     
         25 . The method of  claim 23 , wherein each of the microneedles has a sword shape having a V-type knife edge at a periphery of the microneedle. 
     
     
         26 . The method of  claim 23 , wherein the step of etching is part of a lithographic patterning process. 
     
     
         27 . The method of  claim 23 , wherein the step of etching includes isotropic etching of the layer. 
     
     
         28 . The method of  claim 23  wherein a distal end of at least one microneedle has an approximately hexagon-shaped cross section. 
     
     
         29 . The method of  claim 23 , wherein a distal end of at least one microneedle has a point that is formed at an intersection of at least four surfaces. 
     
     
         30 . The method of  claim 23 , wherein the second plurality of microneedles each extend away from the center of the first closed loop. 
     
     
         31 . The method of  claim 23 , further comprising:
 bending penetrating portions of the first and second pluralities of microneedles away from the plane of the first closed loop.   
     
     
         32 . The method of  claim 23 , wherein a packing density of the microneedles is at least 2 microneedles per square millimeter. 
     
     
         33 - 34 . (canceled) 
     
     
         35 . The method of  claim 23 , further comprising:
 exposing both sides of the layer, separately or simultaneously, to etching conditions, such that the steps of etching occurs on both sides of the layer of material.   
     
     
         36 . The method of  claim 23 , wherein at least some of the microneedles are coated with a substance. 
     
     
         37 . The method of  claim 36 , wherein the substance comprises one or more of lidocaine, bupivacaine, and tetracaine.