Exhibit 4.1

Execution Copy

POSITIVEID CORPORATION

CONVERTIBLE SECURED PROMISSORY NOTE

FOR VALUE RECEIVED, the undersigned, POSITIVEID CORPORATION, a Delaware corporation (the “Company”), promises to pay to Dick Glass (the “Holder”), in lawful money of the United States of America, the principal amount of one hundred fifty thousand dollars ($150,000.00) (the “Principal Amount”), with interest calculated in accordance herewith, on December 31, 2016 (the “Maturity Date”).

This convertible secured promissory note (the “Note”) is being issued pursuant to that certain Stock Purchase Agreement between the Company and Holder (the “Agreement”), dated as of December 22, 2015. Notwithstanding anything in this Note to contrary, this Note shall not be in effect unless and until the transaction contemplated by the Agreement has closed.

(i) The number of shares of Common Stock issuable upon conversion of any Conversion Amount (as defined herein) shall be determined by dividing (x) such Conversion Amount by (y) the Conversion Price. “Conversion Amount” means the sum of (x) portion of the principal to be converted, redeemed or otherwise with respect to which this determination is being made and (y) all accrued and unpaid interest with respect to such portion of the principal amount. “Conversion Price” means, as of any Conversion Date or other date of determination, seventy-five percent (75%) of the average of the three (3) lowest daily VWAPs (volume weighted average price) of each of the ten (10) Trading Days prior to the day that the Holder requests conversion.

(ii) The Company shall not issue any fraction of a share of Common Stock upon any conversion. If the issuance would result in the issuance of a fraction of a share of Common Stock, the Company shall round such fraction of a share of Common Stock up or down to the nearest whole share.

(iii) To convert any Conversion Amount into shares of Common Stock on any date (a “Conversion Date”), the Holder shall deliver, for receipt on or prior to 11:59 p.m., New York time, on such date, a copy of an written notice of conversion stipulating the amount or principal (in dollars) desired to be converted (the “Conversion Notice”) to the Company. The Company shall keep track of the amount outstanding on the Note after any Conversion, based on the Conversion Notices received.

(iv) Upon receipt by the Company from the Holder of a Conversion Notice the Company shall issue and deliver or cause to be issued and delivered to or upon the order of the Holder certificates for the Common Stock issuable upon such conversion within three (3) business days after such receipt (the “Deadline”). If eligible for DWAC transfer, and so requested in the Conversion Notice, the Company shall transmit the shares via DWAC system.

(v) Any conversion will be limited by: (i) Holder may not make more than one conversion every five Trading Days, and (ii) the amount of Conversion Shares at any conversion may not be more than the total number of shares of Common Stock traded over the five Trading Days preceding the Conversion Notice multiplied by five percent (5%).

(vi) The shares of Common Stock issuable upon conversion of this Note may not be sold or transferred unless (i) such shares are sold pursuant to an effective registration statement under the Securities Act or (ii) the Company or its transfer agent shall have been furnished with an opinion of counsel (which opinion shall be in form, substance and scope customary for opinions of counsel in comparable transactions) to the effect that the shares to be sold or transferred may be sold or transferred pursuant to an exemption from such registration or or (iii) such shares are sold or transferred pursuant to Rule 144 under the Act (or a successor rule) (“Rule 144”). Until such time as the shares of Common Stock issuable upon conversion of this Note have been registered under the Act or otherwise may be sold pursuant to Rule 144 without any restriction as to the number of securities as of a particular date that can then be immediately sold, each certificate for shares of Common Stock issuable upon conversion of this Note that has not been so included in an effective registration statement or that has not been sold pursuant to an effective registration statement or an exemption that permits removal of the legend, shall bear a legend substantially in the following form, as appropriate: “NEITHER THE ISSUANCE AND SALE OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE NOR THE SECURITIES INTO WHICH THESE SECURITIES ARE EXERCISABLE HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR THE SECURITIES UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR (B) AN OPINION OF COUNSEL (WHICH COUNSEL SHALL BE SELECTED BY THE HOLDER), IN A GENERALLY ACCEPTABLE FORM, THAT REGISTRATION IS NOT REQUIRED UNDER SAID ACT OR (II) UNLESS SOLD PURSUANT TO RULE 144 OR RULE 144A UNDER SAID ACT.”

(i) if the Company shall fail to pay when due any amount owed on this Note and such failure continues for five (5) Business Days after Holder notifies the Company thereof in writing of such failure;

(ii) if the Company fails to perform or observe any other provision of this Note and such failure continues for thirty (30) calendar days after Holder notifies the Company thereof in writing of such failure;

(iii) if there is a Change of Control of the Company The term “Change of Control” shall mean (i) any consolidation or merger involving the Company pursuant to which the Company's stockholders immediately before such transaction own less than fifty percent (50%) of the voting securities of the surviving entity immediately after such transaction or (ii) the sale of all or substantially all of the assets of the Company;

(iv) if, pursuant to or within the meaning of the United States Bankruptcy Code or any other federal or state law relating to insolvency or relief of debtors (a “Bankruptcy Law”), the Company shall (i) commence a voluntary case or proceeding; (ii) consent to the entry of an order for relief against it in an involuntary case; (iii) consent to the appointment of a trustee, receiver, assignee, liquidator or similar official; (iv) make an assignment for the benefit of its creditors; or (v) admit in writing its inability to pay its debts as they become due; and

(v) if a court of competent jurisdiction enters an order or decree under any Bankruptcy Law that (i) is for relief against the Company in an involuntary case,(ii) appoints a trustee, receiver, assignee, liquidator or similar official for the Company or substantially all of the Company’s properties, or (iii) orders the liquidation of the Company, and in each case the order or decree is not dismissed within 60 Business Days.

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IN WITNESS WHEREOF, the parties hereto have caused this Note to be executed as of the date first written above by their respective officers thereunto duly authorized.