# US 10,371,762 B2 · Identification of molecules based on frequency responses using electromagnetic write-heads and magneto-resistive sensors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,371,762 B2 - Document ID: US10371762B2 - Status: Granted - Kind: B2 - Application number: 15/963,006 - Filed: 2018-04-25 - Published: 2018-08-30 - Granted: 2019-08-06 - Earliest claimed: 2011-06-01 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Allen K. Bates; Anna W. Topol; Daniel J. Winarski - Web page: https://patentgrep.com/patent/US10371762B2 ## CPC - G01R 33/091: {Constructional adaptation of the sensor to specific applications} - G01N 27/72: by investigating magnetic variables - G01R 33/093: {using multilayer structures, e.g. giant magnetoresistance sensors (thin magnetic films H01F10/00)} - G01R 33/1269: {of molecules labeled with magnetic beads (magnetic particles for bio assay G01N33/54326)} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - 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 The inventive concepts presented herein relate to methods of identifying molecules identification of molecules using apparatuses including: electromagnetic write-head(s); magneto-resistive read sensor(s), and processor(s). An exemplary method includes magnetically exciting a molecule to be identified using an alternating magnetic field generated by an electromagnetic write-head, measuring a resonant response of the molecule to be identified using a magneto-resistive read sensor; and comparing, using a processor, the resonant response of the molecule to be identified with a table of known resonant responses to identify a chemical composition of the molecule to be identified. The molecule to be identified may optionally be disposed on a biosample substrate which comprises, or is coupled to, a plurality of servo-alignment marks; and the plurality of servo-alignment marks are configured to facilitate alignment of the electromagnetic write-head with the biosample tracks of the biosample substrate. ## Claims ### Claim 1 A method of identifying a molecule, comprising: magnetically exciting a molecule to be identified using an alternating magnetic field generated by an electromagnetic write-head while scanning one or more biosample tracks of a biosample substrate placed in proximity to the electromagnetic write-head, wherein the molecule to be identified is disposed on a biosample substrate; measuring a resonant response of the molecule to be identified using a magneto-resistive read sensor; and comparing, using a processor, the resonant response of the molecule to be identified with a table of known resonant responses to identify a chemical composition of the molecule to be identified. ### Claim 2 (depends on 1) The method of claim 1, further comprising exposing the molecule to be identified to a DC magnetic field while the molecule is being magnetically excited by the alternating magnetic field to facilitate the measurement of the resonant response. ### Claim 3 (depends on 1) The method of claim 1, further comprising filtering out a DC signal from the resonant response using a Wheatstone bridge. ### Claim 4 (depends on 1) The method of claim 1, further comprising filtering out AC noise signals from the resonant response using a filter selected from the group consisting of a band pass filter, a band block filter, a high-pass filter, a Hamming filter, and a Butterworth filter. ### Claim 5 (depends on 1) The method of claim 1, further comprising amplifying the resonant response using an amplifier. ### Claim 6 A method of identifying a molecule, comprising: magnetically exciting a molecule to be identified using an alternating magnetic field generated by an electromagnetic write-head, wherein the molecule to be identified is disposed on a biosample substrate; measuring a resonant response of the molecule to be identified using a magneto-resistive read sensor; comparing, using a processor, the resonant response of the molecule to be identified with a table of known resonant responses to identify a chemical composition of the molecule to be identified, wherein identifying the chemical composition of the molecule to be identified further comprises calculating, using the processor, a dividend of: one or more Bode plots of the resonant response of the molecule to be identified, and an excitation signal; and comparing, using the processor, the calculated dividend with the table of known resonant responses to identify a chemical composition of the molecule to be identified. ### Claim 7 (depends on 1) The method of claim 1, wherein further comprising normalizing the resonant response of the molecule to be identified. ### Claim 8 (depends on 6) The method of claim 6, further comprising exposing the molecule to be identified to a DC magnetic field while the molecule is being magnetically excited by the alternating magnetic field to facilitate the measurement of the resonant response. ### Claim 9 (depends on 6) The method of claim 6, further comprising filtering out a DC signal from the resonant response using a Wheatstone bridge. ### Claim 10 (depends on 6) The method of claim 6, further comprising filtering out AC noise signals from the resonant response using a filter selected from the group consisting of a band pass filter, a band block filter, a high-pass filter, a Hamming filter, and a Butterworth filter. ### Claim 11 (depends on 6) The method of claim 6, further comprising amplifying the resonant response using an amplifier.