# US 10,871,580 B1 · Metal oxide based radiation sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,871,580 B1 - Document ID: US10871580B1 - Status: Granted - Kind: B1 - Application number: 16/923,725 - Filed: 2020-07-08 - Granted: 2020-12-22 - Earliest claimed: 2020-07-08 - Assignees: King Saud University - Applicants: King Saud University - Inventors: Abdullah Nasser Alodhayb; Hamad Abdulaziz Albrithen; Khaled Zouher Shamma - Web page: https://patentgrep.com/patent/US10871580B1 ## CPC - G01T 1/1606: {with other specified detectors not provided for in the other subgroups of G01T1/16} - G01T 1/02: Dosimeters (G01T1/15 takes precedence) - G01T: MEASUREMENT OF NUCLEAR OR X-RADIATION (radiation analysis of materials, mass spectrometry G01N23/00; tubes for determining the presence, intensity, density or energy of radiation or particles H01J47/00) ## Abstract A metal oxide based radiation sensor includes a titanium dioxide (TiO2) thin film layer on a microcantilever surface. The TiO2 thin film layer initially comprises anatase and rutile crystal structures. Exposure to radiation, such as gamma radiation, results in changes in structural features and mechanical behaviors of the metal oxide based radiation sensor. In particular, the resonant frequency changes with exposure to radiation dosages. The structural and mechanical behaviors of the metal oxide based radiation sensor change proportionally with dosage within a range of dosages. ## Claims ### Claim 1 A radiation sensor comprising: a substrate; a microcantilever having one end operatively coupled to the substrate; and a metal oxide layer arranged on a surface of the microcantiever, wherein the metal oxide layer comprises the metal oxide in at least one crystal form, the at least one crystal form being capable of transformation to a different form upon exposure to a radiation to be detected. ### Claim 2 (depends on 1) The radiation sensor of claim 1, wherein the metal oxide is titanium dioxide. ### Claim 3 (depends on 2) The radiation sensor of claim 2, wherein the at least one crystal form includes rutile. ### Claim 4 (depends on 2) The radiation sensor of claim 2, wherein the at least one crystal form includes rutile and anatase. ### Claim 5 (depends on 2) The radiation sensor of claim 2, wherein the microcantilever comprises a silicon based material. ### Claim 6 (depends on 5) The radiation sensor of claim 5, wherein the metal oxide layer has a first average thickness in a direction normal to the surface of the microcantilever on which the metal oxide layer is arranged and the microcantilever has a second average thickness in said direction, and the ratio of the first thickness to the second thickness is between 1:50 and 1:1. ### Claim 7 (depends on 6) The radiation sensor of claim 6 wherein the ratio of the first thickness to the second thickness is between 1:20 and 1:5. ### Claim 8 (depends on 1) The radiation sensor of claim 1, wherein the first thickness is uniform over the surface of the microcantilever on which the metal oxide layer is arranged. ### Claim 9 (depends on 1) The radiation sensor of claim 1, wherein the metal oxide layer comprises crystal grains having an initial grain size before exposure to the radiation to be detected and the crystal grains have a second grain size after exposure to the radiation to be detected, wherein the second grain size is smaller than the initial grain size. ### Claim 10 (depends on 1) A device comprising the radiation sensor of claim 1 and a structure for immobilizing the radiation sensor and enclosing the radiation sensor, the chamber being penetrable to the radiation to be detected. ### Claim 11 (depends on 10) The device of claim 10, wherein the chamber is configured to be worn on a person. ### Claim 12 (depends on 1) A method for detecting radiation exposure comprising steps of: measuring a detectable quantity of radiation in the radiation sensor of claim 1 to get a base value; exposing the radiation sensor to radiation; measuring the detectable quantity of radiation exposed to the radiation sensor to get an exposed value; and calculating a difference between the base value and the exposed value as a change in the detectable quantity of the radiation sensor. ### Claim 13 (depends on 12) The method of claim 12, wherein the detectable quantity is the resonant frequency of the microcantilever. ### Claim 14 A method of fabricating a radiation sensor comprising: providing a microcantilever having one end coupled to a substrate; and coating a side of the microcantilever with a metal oxide layer, wherein the metal oxide layer comprises the metal oxide in at least one crystal form, the at least one crystal form being capable of transformation to a different form upon exposure to a radiation to be detected. ### Claim 15 (depends on 14) The method of claim 14, wherein the metal oxide layer is coated on the side of the microcantilever by means of atomic layer deposition. ### Claim 16 (depends on 14) The method of claim 14, wherein the metal oxide layer ranges from about 50 to about 200 nm thick.