Form 8-K

8-K — ClearSign Technologies Corp

Accession: 0001104659-26-071865

Filed: 2026-06-09

Period: 2026-06-08

CIK: 0001434524

SIC: 3823 (INDUSTRIAL INSTRUMENTS FOR MEASUREMENT, DISPLAY, AND CONTROL)

Item: Submission of Matters to a Vote of Security Holders

Item: Financial Statements and Exhibits

Documents

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of report (Date of earliest event reported):

June 8, 2026

CLEARSIGN TECHNOLOGIES CORPORATION

(Exact name of registrant as specified in charter)

Delaware

001-35521

26-2056298

(State or other jurisdiction of

incorporation)

(Commission File Number)

(IRS Employer

Identification No.)

8023 E. 63rd Place, Suite 101

Tulsa,

Oklahoma 74133

(Address of principal executive offices

and zip code)

(918) 500-7312

(Registrant's telephone number, including area code)

Check the appropriate box below if the Form 8-K filing is intended

to simultaneously satisfy the filing obligation of the Registrant under any of the following provisions (see General Instruction A.2 below).

Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR240.14a-12)

Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

Pre-commencement communications pursuant to Rule 13e-4(c) under the

Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading Symbol(s)

Name

of each exchange on which

registered

Common Stock

CLIR

The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth

company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange

Act of 1934 (§240.12b-2 of this chapter).

Emerging growth

company ¨

If an emerging growth company, indicate by check mark if the registrant

has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant

to Section 13(a) of the Exchange Act. ¨

Item 5.07

Submission of Matters to a Vote of Security Holders.

June 8, 2026, ClearSign Technologies Corporation (the “Company”) held its 2026 annual meeting of stockholders (the “Annual

Meeting”). At the beginning of the Annual Meeting, there were 3,666,852 shares of the Company’s common stock, par value $0.0001

per share, present or represented by proxy, which represented 67.79% of the voting power of the Company’s outstanding shares of voting

stock entitled to vote at the Annual Meeting, and which constituted a quorum for the transaction of business. Holders of common stock

were entitled to one vote for each share of common stock held as of the close of business on April 13, 2026. Summarized below are the

final voting results for each proposal submitted to a vote of the stockholders at the Annual Meeting. The five proposals below are each

described in more detail in the definitive proxy statement on Schedule 14A filed with the Securities and Exchange Commission on April

28, 2026.

Proposal 1. Election

of Directors.

Nominee Name

For

Against

Abstentions

Broker Non-Votes

Louis J. Basenese

1,808,414

370,481

34,369

1,453,588

Colin James Deller

1,995,376

217,011

877

1,453,588

Anthony DiGiandomenico

1,775,452

418,786

19,026

1,453,588

G. Todd Silva

1,829,493

364,781

18,990

1,453,588

Each

of the four nominees standing for re-election as a director was elected to serve on the Company’s board of directors until the election

and qualification of his successor or until his earlier death, resignation, or removal.

Proposal 2. The

approval, on an advisory basis, of the appointment of BPM CPA LLP as the Company’s independent registered public accounting firm

for the fiscal year ending December 31, 2026.

For

Against

Abstentions

3,263,437

394,510

8,905

There were no broker non-votes

on this proposal.

The

stockholders approved, on an advisory basis, the appointment of BPM CPA LLP as the Company’s independent registered public accounting

firm for the fiscal year ending December 31, 2026.

Proposal 3. The

approval of the amended and restated ClearSign Technologies Corporation 2021 Equity Incentive Plan (the “A&R 2021 Plan”).

For

Against

Abstentions

Broker Non-Votes

1,546,015

659,279

7,970

1,453,588

The

stockholders approved the A&R 2021 Plan.

Proposal 4. The

approval, on an advisory basis, of the compensation paid to the Company’s named executive officers.

For

Against

Abstentions

Broker Non-Votes

1,826,151

379,205

7,908

1,453,588

The

stockholders approved, on an advisory basis, the compensation paid to the Company’s named executive officers.

Proposal 5. The

approval of one or more adjournments of the Annual Meeting to a later date or dates to solicit additional proxies if there are insufficient

votes to approve the A&R 2021 Plan or in the absence of a quorum (the “Adjournment Proposal”).

For

Against

Abstentions

Broker Non-Votes

1,596,167

570,671

46,426

1,453,588

The stockholders approved

the Adjournment Proposal.

Item 9.01

Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No.

Description

104

Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf

by the undersigned hereunto duly authorized.

Dated: June 9, 2026

CLEARSIGN TECHNOLOGIES CORPORATION

By:

/s/ Colin James Deller

Name:

Colin James Deller

Title:

Chief Executive Officer

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Entity Registrant Name

CLEARSIGN TECHNOLOGIES CORPORATION

Entity Central Index Key

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Entity Tax Identification Number

26-2056298

Entity Incorporation, State or Country Code

Entity Address, Address Line One

8023 E. 63rd Place, Suite 101

Entity Address, City or Town

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Entity Address, State or Province

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City Area Code

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Local Phone Number

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