# EDGAR Filing Document

**Accession Number:** 0001434524
**File Stem:** 0001104659-25-085648
**Filing Date:** 2025-8
**Character Count:** 6324
**Document Hash:** 4f2bc6bd05627235824da422380b152d
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-25-085648.hdr.sgml**: 20250829

**ACCESSION NUMBER**: 0001104659-25-085648

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 12

**CONFORMED PERIOD OF REPORT**: 20250826

**ITEM INFORMATION**: Other Events

**FILED AS OF DATE**: 20250829

**DATE AS OF CHANGE**: 20250829

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** ClearSign Technologies Corp
- **CENTRAL INDEX KEY:** 0001434524
- **STANDARD INDUSTRIAL CLASSIFICATION:** INDUSTRIAL INSTRUMENTS FOR MEASUREMENT, DISPLAY, AND CONTROL [3823]
- **ORGANIZATION NAME:** 08 Industrial Applications and Services
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-35521
- **FILM NUMBER:** 251280840

**BUSINESS ADDRESS:**
- **STREET 1:** 8023 E. 63RD PLACE, SUITE 101
- **CITY:** TULSA
- **STATE:** OK
- **ZIP:** 74133
- **BUSINESS PHONE:** (918) 236-6461

**MAIL ADDRESS:**
- **STREET 1:** 8023 E. 63RD PLACE, SUITE 101
- **CITY:** TULSA
- **STATE:** OK
- **ZIP:** 74133

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** CLEARSIGN COMBUSTION CORP
- **DATE OF NAME CHANGE:** 20080507

?xml version='1.0' encoding='ASCII'?

**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): August 26, 2025**

**CLEARSIGN TECHNOLOGIES CORPORATION**

**(Exact name of registrant as specified in charter)**

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| | | |
|:---|:---|:---|
| **Delaware** | **001-35521** | **26-2056298** |
| **(State or other jurisdiction of <br> incorporation)** | **(Commission File Number)** | **(IRS Employer <br> Identification No.)** |

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**8023 E. 63rd Place, Suite 101**

**Tulsa** **, Oklahoma 74133**

**(Address of Principal Executive Offices) (Zip Code)**

**(918) 236-6461**

**(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 240.13(e)-4(c))

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

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| | | |
|:---|:---|:---|
| **Title of each class** | **Trading Symbol(s)** | **Name of each exchange on which <br> registered** |
| **Common Stock** | **CLIR** | **The Nasdaq Stock Market LLC** |

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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. ◻

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| | |
|:---|:---|
| **Item 8.01** | **Other Events.** |

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As previously disclosed, on August 8, 2025, ClearSign Technologies Corporation (the "Company") received a notice from the Listing Qualifications Department of the Nasdaq Stock Market LLC ("Nasdaq") stating that the Company is not in compliance with the board of directors independence requirement set forth in Nasdaq Listing Rule 5605(b)(1) and the audit committee composition requirement set forth in Nasdaq Listing Rule 5605(c)(2)(A) (collectively, the "Nasdaq Composition Requirements") due to the resignations of Catharine M. de Lacy and Judith S. Schrecker from the Company's board of directors (the "Board"), effective as of August 4, 2025.

On August 26, 2025, the Board held a meeting and, in light of updated materials reviewed by the Board pertinent to the independence determination of Anthony DiGiandomenico, a member of the Board, it determined that Mr. DiGiandomenico is an "independent director" under Nasdaq Listing Rule 5605(a)(2) and Rule 10A-3 under the Securities Exchange Act of 1934, as amended. As a result of such determinations, the Board appointed Mr. DiGiandomenico to the Audit and Risk Committee of the Board (the "Audit Committee"), effective immediately. In the same meeting, the Board also appointed G. Todd Silva, an "independent director" and member of the Audit Committee, as the Audit Committee's chairperson and designated him as the committee's "audit committee financial expert," as such term is defined in Item 407(d)(5) of Regulation S-K, effective immediately.

Subsequently, on August 28, 2025, the Company notified Nasdaq of the actions described above, and, as a result, on the same date, Nasdaq issued a letter to the Company stating that, based on the Company's notification, it had regained compliance with the Nasdaq Composition Requirements as of such date. Notwithstanding the foregoing, the Board still intends to fill the one vacancy on the Board resulting from the resignations of Mss. de Lacy and Schrecker after taking into account the reduction in size of the Board from six to five directors effective as of August 6, 2025.

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| | |
|:---|:---|
| **Item 9.01** | **Financial Statements and Exhibits.** |

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**(d) Exhibits.**

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| | |
|:---|:---|
| **Exhibit No.** | **Description** |
| 104 | Cover Page Interactive Data File (embedded within the Inline XBRL document). |

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**SIGNATURE**

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this Current Report to be signed on its behalf by the undersigned hereunto duly authorized.

Dated: August 29, 2025

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| | |
|:---|:---|
| **CLEARSIGN TECHNOLOGIES CORPORATION** | **CLEARSIGN TECHNOLOGIES CORPORATION** |
| By: | /s/ Colin James Deller |
| Name: | Colin James Deller |
| Title: | Chief Executive Officer |

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