<?xml version="1.0" encoding="US-ASCII" ?>
    <!-- Field: Doc-Info; Name: Generator; Value: GoFiler Complete; Version: 6.0b -->
    <!-- Field: Doc-Info; Name: VendorURI; Value: https://www.novaworks.com -->
    <!-- Field: Doc-Info; Name: Status; Value: 0x00000000 -->
    <!-- Field: Doc-Info; Name: Misc; Value: 96Mps7xRiXgen8uDanwsWaqPybP9z5Z8WekhvWB6bUlKTyQqXIsvzCRTuOuW0RgL -->
<schema xmlns="http://www.w3.org/2001/XMLSchema" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xbrldi="http://xbrl.org/2006/xbrldi" xmlns:dei="http://xbrl.sec.gov/dei/2024" xmlns:us-gaap="http://fasb.org/us-gaap/2024" xmlns:srt="http://fasb.org/srt/2024" xmlns:srt-types="http://fasb.org/srt-types/2024" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2022-03-31" xmlns:SINT="http://sintx.com/20250331" elementFormDefault="qualified" targetNamespace="http://sintx.com/20250331">
    <annotation>
      <appinfo>
        <link:roleType roleURI="http://sintx.com/role/Cover" id="Cover">
          <link:definition>00000001 - Document - Cover</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/BalanceSheets" id="BalanceSheets">
          <link:definition>00000002 - Statement - Condensed Consolidated Balance Sheets (Unaudited)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/BalanceSheetsParenthetical" id="BalanceSheetsParenthetical">
          <link:definition>00000003 - Statement - Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/StatementsOfOperations" id="StatementsOfOperations">
          <link:definition>00000004 - Statement - Condensed Consolidated Statements of Operations (Unaudited)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/StatementsOfStockholdersEquity" id="StatementsOfStockholdersEquity">
          <link:definition>00000005 - Statement - Condensed Consolidated Statements of Stockholders' Equity (Unaudited)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/StatementsOfCashFlows" id="StatementsOfCashFlows">
          <link:definition>00000006 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/OrganizationAndSummaryOfSignificantAccountingPolicies" id="OrganizationAndSummaryOfSignificantAccountingPolicies">
          <link:definition>999007 - Disclosure - Organization and Summary of Significant Accounting Policies</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/DispositionOfTat" id="DispositionOfTat">
          <link:definition>999008 - Disclosure - Disposition of TA&amp;T</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/BasicAndDilutedNetIncomeLossPerCommonShare" id="BasicAndDilutedNetIncomeLossPerCommonShare">
          <link:definition>999009 - Disclosure - Basic and Diluted Net Income (Loss) per Common Share</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/Inventories" id="Inventories">
          <link:definition>999010 - Disclosure - Inventories</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/FairValueMeasurements" id="FairValueMeasurements">
          <link:definition>999011 - Disclosure - Fair Value Measurements</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/AccruedLiabilities" id="AccruedLiabilities">
          <link:definition>999012 - Disclosure - Accrued Liabilities</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/Debt" id="Debt">
          <link:definition>999013 - Disclosure - Debt</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/Equity" id="Equity">
          <link:definition>999014 - Disclosure - Equity</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/Stock-basedCompensation" id="Stock-basedCompensation">
          <link:definition>999015 - Disclosure - Stock-Based Compensation</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/CommitmentsAndContingencies" id="CommitmentsAndContingencies">
          <link:definition>999016 - Disclosure - Commitments and Contingencies</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/Leases" id="Leases">
          <link:definition>999017 - Disclosure - Leases</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/SubsequentEvents" id="SubsequentEvents">
          <link:definition>999018 - Disclosure - Subsequent Events</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/OrganizationAndSummaryOfSignificantAccountingPoliciesPolicies" id="OrganizationAndSummaryOfSignificantAccountingPoliciesPolicies">
          <link:definition>999019 - Disclosure - Organization and Summary of Significant Accounting Policies (Policies)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/DispositionOfTatTables" id="DispositionOfTatTables">
          <link:definition>999020 - Disclosure - Disposition of TA&amp;T (Tables)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/BasicAndDilutedNetIncomeLossPerCommonShareTables" id="BasicAndDilutedNetIncomeLossPerCommonShareTables">
          <link:definition>999021 - Disclosure - Basic and Diluted Net Income (Loss) per Common Share (Tables)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/InventoriesTables" id="InventoriesTables">
          <link:definition>999022 - Disclosure - Inventories (Tables)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/FairValueMeasurementsTables" id="FairValueMeasurementsTables">
          <link:definition>999023 - Disclosure - Fair Value Measurements (Tables)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/AccruedLiabilitiesTables" id="AccruedLiabilitiesTables">
          <link:definition>999024 - Disclosure - Accrued Liabilities (Tables)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/Stock-basedCompensationTables" id="Stock-basedCompensationTables">
          <link:definition>999025 - Disclosure - Stock-Based Compensation (Tables)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/LeasesTables" id="LeasesTables">
          <link:definition>999026 - Disclosure - Leases (Tables)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/OrganizationAndSummaryOfSignificantAccountingPoliciesDetailsNarrative" id="OrganizationAndSummaryOfSignificantAccountingPoliciesDetailsNarrative">
          <link:definition>999027 - Disclosure - Organization and Summary of Significant Accounting Policies (Details Narrative)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/ScheduleOfMajorClassesOfAssetsAndLiabilitiesOfTaTAtDateOfSaleDetails" id="ScheduleOfMajorClassesOfAssetsAndLiabilitiesOfTaTAtDateOfSaleDetails">
          <link:definition>999028 - Disclosure - Schedule of Major Classes of Assets and Liabilities of TA &amp; T at the Date of Sale (Details)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/ScheduleOfBasicAndDilutedLossPerShareDetails" id="ScheduleOfBasicAndDilutedLossPerShareDetails">
          <link:definition>999029 - Disclosure - Schedule of Basic and Diluted Loss Per Share (Details)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/BasicAndDilutedNetIncomeLossPerCommonShareDetailsNarrative" id="BasicAndDilutedNetIncomeLossPerCommonShareDetailsNarrative">
          <link:definition>999030 - Disclosure - Basic and Diluted Net Income (Loss) per Common Share (Details Narrative)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/ScheduleOfComponentsOfInventoryDetails" id="ScheduleOfComponentsOfInventoryDetails">
          <link:definition>999031 - Disclosure - Schedule of Components of Inventory (Details)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/InventoriesDetailsNarrative" id="InventoriesDetailsNarrative">
          <link:definition>999032 - Disclosure - Inventories (Details Narrative)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/ScheduleOfFinancialLiabilitiesMeasuredAtFairValueOnRecurringBasisByLevelWithinFairValueHierarchyDetails" id="ScheduleOfFinancialLiabilitiesMeasuredAtFairValueOnRecurringBasisByLevelWithinFairValueHierarchyDetails">
          <link:definition>999033 - Disclosure - Schedule of Financial Liabilities Measured at Fair Value on Recurring Basis by Level Within Fair Value Hierarchy (Details)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/ScheduleOfFairValueMeasurementHierarchyOfDerivativeLiabilityDetails" id="ScheduleOfFairValueMeasurementHierarchyOfDerivativeLiabilityDetails">
          <link:definition>999034 - Disclosure - Schedule of Fair Value Measurement Hierarchy of Derivative Liability (Details)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/ScheduleOfAssumptionsUsedInEstimatingFairValueDetails" id="ScheduleOfAssumptionsUsedInEstimatingFairValueDetails">
          <link:definition>999035 - Disclosure - Schedule of Assumptions Used in Estimating Fair Value (Details)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/ScheduleOfAccruedLiabilitiesDetails" id="ScheduleOfAccruedLiabilitiesDetails">
          <link:definition>999036 - Disclosure - Schedule of Accrued Liabilities (Details)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/DebtDetailsNarrative" id="DebtDetailsNarrative">
          <link:definition>999037 - Disclosure - Debt (Details Narrative)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/EquityDetailsNarrative" id="EquityDetailsNarrative">
          <link:definition>999038 - Disclosure - Equity (Details Narrative)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/ScheduleOfStockOptionActivityDetails" id="ScheduleOfStockOptionActivityDetails">
          <link:definition>999039 - Disclosure - Schedule of Stock Option Activity (Details)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/ScheduleOfUnrecognizedStock-basedCompensationDetails" id="ScheduleOfUnrecognizedStock-basedCompensationDetails">
          <link:definition>999040 - Disclosure - Schedule of Unrecognized Stock-based Compensation (Details)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/Stock-basedCompensationDetailsNarrative" id="Stock-basedCompensationDetailsNarrative">
          <link:definition>999041 - Disclosure - Stock-Based Compensation (Details Narrative)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/ScheduleOfOperatingLeaseFutureMinimumPaymentsDetails" id="ScheduleOfOperatingLeaseFutureMinimumPaymentsDetails">
          <link:definition>999042 - Disclosure - Schedule of Operating Lease Future Minimum Payments (Details)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://sintx.com/role/LeasesDetailsNarrative" id="LeasesDetailsNarrative">
          <link:definition>999043 - Disclosure - Leases (Details Narrative)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:linkbaseRef xlink:type="simple" xlink:href="sint-20250331_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:title="Presentation Links" />
        <link:linkbaseRef xlink:type="simple" xlink:href="sint-20250331_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:title="Label Links" />
        <link:linkbaseRef xlink:type="simple" xlink:href="sint-20250331_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:title="Calculation Links" />
        <link:linkbaseRef xlink:type="simple" xlink:href="sint-20250331_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:title="Definition Links" />
      </appinfo>
    </annotation>
    <import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" />
    <import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" />
    <import namespace="http://xbrl.sec.gov/dei/2024" schemaLocation="https://xbrl.sec.gov/dei/2024/dei-2024.xsd" />
    <import namespace="http://fasb.org/us-gaap/2024" schemaLocation="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd" />
    <import namespace="http://fasb.org/us-types/2024" schemaLocation="https://xbrl.fasb.org/us-gaap/2024/elts/us-types-2024.xsd" />
    <import namespace="http://www.xbrl.org/dtr/type/2022-03-31" schemaLocation="https://www.xbrl.org/dtr/type/2022-03-31/types.xsd" />
    <import namespace="http://xbrl.sec.gov/country/2024" schemaLocation="https://xbrl.sec.gov/country/2024/country-2024.xsd" />
    <import namespace="http://fasb.org/srt/2024" schemaLocation="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd" />
    <import namespace="http://fasb.org/srt-types/2024" schemaLocation="https://xbrl.fasb.org/srt/2024/elts/srt-types-2024.xsd" />
    <element id="SINT_SeriesBConvertiblePreferredStockMember" name="SeriesBConvertiblePreferredStockMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_SeriesCConvertiblePreferredStockMember" name="SeriesCConvertiblePreferredStockMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_SeriesDConvertiblePreferredStockMember" name="SeriesDConvertiblePreferredStockMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_GrantAndContractMember" name="GrantAndContractMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_ATMAgreementMember" name="ATMAgreementMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_MaximGroupLLCMember" name="MaximGroupLLCMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_CommonStockAndPrefundedWarrantsMember" name="CommonStockAndPrefundedWarrantsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_ClassEAndClassFWarrantsMember" name="ClassEAndClassFWarrantsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_CommonStockWarrantsMember" name="CommonStockWarrantsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_DerivativeLiabilitiesForCommonStockWarrantsMember" name="DerivativeLiabilitiesForCommonStockWarrantsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_AgentWarrantOfferingMember" name="AgentWarrantOfferingMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_PreFundedWarrantMember" name="PreFundedWarrantMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_BlackScholesMertonValuationModelMember" name="BlackScholesMertonValuationModelMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_PersonalLoansMember" name="PersonalLoansMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_InsurancePremiumFinanceArrangementsMember" name="InsurancePremiumFinanceArrangementsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_DirectorAndOfficerProfessionalLiabilityInsuranceMember" name="DirectorAndOfficerProfessionalLiabilityInsuranceMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_TwoThousandTwentyFourAprilRegisteredOfferingMember" name="TwoThousandTwentyFourAprilRegisteredOfferingMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_TwoThousandTwentyFourFebruaryRegisteredOfferingMember" name="TwoThousandTwentyFourFebruaryRegisteredOfferingMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_ClassEWarrantsMember" name="ClassEWarrantsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_ClassFWarrantsMember" name="ClassFWarrantsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_CommonUnitMember" name="CommonUnitMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_PreFundedWarrantUnitMember" name="PreFundedWarrantUnitMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_ClassEAndFWarrantsMember" name="ClassEAndFWarrantsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_ClassEWarrantMember" name="ClassEWarrantMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_PreFundedWarrantsMember" name="PreFundedWarrantsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_TwoThousandTwentyFourMarchRegisteredOfferingMember" name="TwoThousandTwentyFourMarchRegisteredOfferingMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_TwoThousandAndTwentyOneEquityDistributionAgreementMember" name="TwoThousandAndTwentyOneEquityDistributionAgreementMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_NonExecutiveMember" name="NonExecutiveMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_EmployeeStockGrantsMember" name="EmployeeStockGrantsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_IndustrialLeaseAgreementMember" name="IndustrialLeaseAgreementMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_GrantExpenses" name="GrantExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_ChangeInFairValueOfDerivativeLiabilities" name="ChangeInFairValueOfDerivativeLiabilities" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_OfferingCostsAssociatedWithDerivativeWarrantLiabilities" name="OfferingCostsAssociatedWithDerivativeWarrantLiabilities" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_StockIssuedDuringPeriodValueCashlessExerciseOfWarrants" name="StockIssuedDuringPeriodValueCashlessExerciseOfWarrants" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_StockIssuedDuringPeriodSharesCashlessExerciseOfWarrants" name="StockIssuedDuringPeriodSharesCashlessExerciseOfWarrants" nillable="true" xbrli:periodType="duration" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_PurchaseOfCommonStockIntoTreasury" name="PurchaseOfCommonStockIntoTreasury" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_LossOnDisposalOfSubsidiary" name="LossOnDisposalOfSubsidiary" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_StockBasedCompensationNonemployee" name="StockBasedCompensationNonemployee" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_ProceedsFromIssuanceOfCommonStockInConnectionWithExerciseOfWarrants" name="ProceedsFromIssuanceOfCommonStockInConnectionWithExerciseOfWarrants" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_IncreaseInPropertyPlantAndEquipmentFromAccrual" name="IncreaseInPropertyPlantAndEquipmentFromAccrual" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_DebtIssuedForPrepaidInsurance" name="DebtIssuedForPrepaidInsurance" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_AgentWarrantOfferingCostAllocatedToEquity" name="AgentWarrantOfferingCostAllocatedToEquity" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_RightOfUseAssetForAmendedLeaseLiabilityDecrease" name="RightOfUseAssetForAmendedLeaseLiabilityDecrease" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_NoncashDisposalOfSubsidiaryAssets" name="NoncashDisposalOfSubsidiaryAssets" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_NoncashDisposalOfSubsidiaryLiabilities" name="NoncashDisposalOfSubsidiaryLiabilities" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_DisclosureLeasesAbstract" name="DisclosureLeasesAbstract" abstract="true" nillable="true" xbrli:periodType="duration" type="xbrli:stringItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_ReverseStockSplitPolicyTextBlock" name="ReverseStockSplitPolicyTextBlock" nillable="true" xbrli:periodType="duration" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_LiquidityAndCapitalResourcesPolicyTextBlock" name="LiquidityAndCapitalResourcesPolicyTextBlock" nillable="true" xbrli:periodType="duration" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_PublicFloat" name="PublicFloat" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_OfferingFeesAndExpenses" name="OfferingFeesAndExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_OfferingExpensesPayable" name="OfferingExpensesPayable" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_NetIncomeEffectOfDilutiveWarrantSecurities" name="NetIncomeEffectOfDilutiveWarrantSecurities" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_NetIncomeEffectOfDilutiveWarrantSecuritiesPerShare" name="NetIncomeEffectOfDilutiveWarrantSecuritiesPerShare" nillable="true" xbrli:periodType="duration" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_InventoryTotal" name="InventoryTotal" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityExerciseOfWarrants" name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityExerciseOfWarrants" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPeriodOther" name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPeriodOther" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_AccruedPayableCurrent" name="AccruedPayableCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_UpFrontInsurancePremium" name="UpFrontInsurancePremium" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_FinancedInsurancePremium" name="FinancedInsurancePremium" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_PublicOfferingUnits" name="PublicOfferingUnits" nillable="true" xbrli:periodType="instant" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_ReimbursementOfExpensesAndLegalFees" name="ReimbursementOfExpensesAndLegalFees" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_AvailableForSaleSecuritiesAmount" name="AvailableForSaleSecuritiesAmount" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageGrantedRemainingContractualTerm2" name="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageGrantedRemainingContractualTerm2" nillable="true" xbrli:periodType="duration" type="xbrli:durationItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_NoncashOperatingLeaseExpense" name="NoncashOperatingLeaseExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_NoncashDisposalOfSubsidiary" name="NoncashDisposalOfSubsidiary" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_PublicFloatThreshold" name="PublicFloatThreshold" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="SINT_ResearchCollaborationAgreementMember" name="ResearchCollaborationAgreementMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
</schema>
