An apparatus and associated methods

Patent metadata

Field	Value
Publication number	US-2017184528-A1
Application number	US-201415312656-A
Country	US
Kind code	A1
Filing date	Jul 25, 2014
Priority date	May 27, 2014
Publication date	Jun 29, 2017
Grant date	—

Abstract

A percolation network of functionalised reduced graphene oxide flakes, the percolation network configured to allow for hopping of charge carriers between adjacent reduced graphene oxide flakes to enable a flow of charge carriers through the percolation network, and wherein the reduced graphene oxide flakes are functionalised to facilitate detectable changes in the flow of charge carriers in response to a stimulus to the percolation network.

First claim

1 - 35 . (canceled)

36 . A percolation network comprising reduced graphene oxide flakes, the percolation network configured to allow for hopping of charge carriers between adjacent reduced graphene oxide flakes to enable a flow of charge carriers through the percolation network, and wherein the reduced graphene oxide flakes are functionalised to facilitate detectable changes in the flow of charge carriers in response to a stimulus to the percolation network.

37 . The percolation network of claim 36 , wherein the reduced graphene oxide flakes are functionalised to comprise a substantially even distribution of reduced graphene oxide flakes.

38 . The percolation network of claim 37 , wherein the substantially even distribution comprises one or more of: a substantially regular spacing between adjacent reduced graphene oxide flakes; and a substantial non-clustering of reduced graphene oxide flakes.

39 . The percolation network of claim 37 , wherein the substantially even distribution applies to one or more of at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% and 98% of the reduced graphene oxide flakes.

40 . The percolation network of claim 36 , wherein the reduced graphene oxide flakes are substantially planar, and wherein the reduced graphene oxide flakes are functionalised such that planes of the reduced graphene oxide flakes are aligned substantially parallel to one another.

41 . The percolation network of claim 40 , wherein the planes of one or more of at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% and 98% of the reduced graphene oxide flakes are aligned substantially parallel to one another.

42 . The percolation network of claim 40 , wherein the planes of the reduced graphene oxide flakes are aligned to within one or more of at least 5°, 10°, 15°, 20°, 25°, 30°, 35° and 40° of one another.

43 . The percolation network of claim 36 , wherein the reduced graphene oxide flakes are functionalised such that the percolation network comprises an overlapping stacked arrangement of the reduced graphene oxide flakes.

44 . The percolation network of claim 43 , wherein one or more of at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% and 98% of the reduced graphene oxide flakes overlap with another reduced graphene oxide flake of the percolation network.

45 . The percolation network of claim 36 , wherein the percolation network has a predetermined thickness associated with the detection of a particular stimulus.

46 . The percolation network of claim 45 , wherein the predetermined thickness is such that the reduced graphene oxide flakes are functionalised to selectively facilitate detectable changes in the flow of charge carriers in response to the particular stimulus.

47 . The percolation network of claim 45 , wherein the particular stimulus is humidity, and the associated predetermined thickness is one or more of 5 nm-250 nm and 100 nm-200 nm.

48 . The percolation network of claim 45 , wherein the particular stimulus is temperature, and the associated predetermined thickness is one or more of at least 500 nm and 500 nm-1000 nm.

49 . The percolation network of claim 45 , wherein the particular stimulus is light or strain, and the associated predetermined thickness is one or more of at least 500 nm and 500 nm-2000 nm.

50 . An apparatus comprising a percolation network comprising reduced graphene oxide flakes, the percolation network configured to allow for hopping of charge carriers between adjacent reduced graphene oxide flakes to enable a flow of charge carriers through the percolation network, and wherein the reduced graphene oxide flakes are functionalised to facilitate detectable changes in the flow of charge carriers in response to a stimulus to the percolation network.

51 . The apparatus of claim 50 further comprises at least another percolation network giving the apparatus with two or more percolation networks, each percolation network having a predetermined thickness associated with the detection of a particular respective stimulus.

52 . The apparatus of claim 51 , wherein the percolation networks are arranged to form a stack or an array.

53 . The apparatus of claim 52 , wherein the uppermost percolation network of the stack has a predetermined thickness associated with the detection of humidity, and wherein the apparatus comprises a passivation layer on top of the uppermost percolation network which is sufficiently porous to allow exposure of the uppermost percolation network to the air of the surrounding environment to enable the detection of humidity.

54 . The apparatus of claim 52 , wherein a percolation network of the stack has a predetermined thickness associated with the detection of light, and wherein each of the layers of the apparatus above the percolation network are sufficiently optically transparent to allow exposure of the percolation network to incident light from the surrounding environment to enable detection of the incident light.

55 . The apparatus of any of claim 52 , wherein the apparatus comprises one or more electrically insulating layers configured to separate adjacent percolation networks of the stack.

Assignees

• Nokia Technologies Oy

Inventors

• Haque Samiul Md
• Spigone Elisabetta
• Kivioja Jani

Classifications

• G01K7/16

  using resistive elements · CPC title

• H01L51/0045

  Electricity · mapped topic

• C01B31/04

  Chemistry & Metallurgy · mapped topic

• G01N27/048 Primary

  for determining moisture content of the material · CPC title

• H01L51/0575

  Electricity · mapped topic