PATENT SECURITY AGREEMENT

This PATENT SECURITY AGREEMENT (this “ Patent Security Agreement ”) is made this 4 th day of September, 2009, among the Grantors listed on the signature pages hereof (collectively, jointly and severally, “ Grantors ” and each individually “Grantor”), and DMRJ GROUP, LLC (together with its successors, the “ Secured Party ”).

WHEREAS , the Secured Party is the holder of that certain Revolving Credit Promissory Note bearing even date herewith in the principal amount of $3,000,000 (as may be amended, restated, supplemented, replaced or otherwise modified from time to time, the “ Note ”) issued or to be issued by the Implant Sciences Corporation (“ Company ”) pursuant to the terms of the Credit Agreement bearing even date herewith (as may be amended, restated, supplemented, replaced or otherwise modified from time to time, the “ Credit Agreement ”) by and between the Company, as borrower, Secured Party, as lender, and C Acquisition Corp., Accurel Systems International Corporation, and IMX Acquisition Corp. as guarantors (collectively, the “ Guarantors ”) and

WHEREAS , pursuant to the terms and conditions of the Credit Agreement, the Secured Party has agreed to extend a loan to the Company, repayment of which is evidenced by the Note, and

WHEREAS , in order to induce the Secured Party to enter into the Note, the Credit Agreement and the other Transaction Documents and to induce the Secured Party to make financial accommodations to the Company as provided for in the Credit Agreement, Grantors have executed and delivered to Secured Party that certain Security Agreement of even date herewith (including all annexes, exhibits or schedules thereto, as from time to time amended, restated, supplemented or otherwise modified, the “ Security Agreement ”);

WHEREAS , pursuant to the Security Agreement, Grantors are required to execute and deliver to Secured Party this Patent Security Agreement;

NOW, THEREFORE , in consideration of the premises and mutual covenants herein contained and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, each Grantor hereby agrees as follows:

1.   DEFINED TERMS .  All capitalized terms used but not otherwise defined herein have the meanings given to them in the Security Agreement or the Note or the Credit Agreement.

2.   GRANT OF SECURITY INTEREST IN PATENT COLLATERAL .  Each Grantor hereby unconditionally grants, assigns and pledges to Secured Party a Security Interest in all of such Grantor’s right, title and interest in and to the following, whether now owned or hereafter acquired or arising and wherever located (collectively, the “ Patent Collateral ”):

(a)   all of its Patents including those referred to on Schedule I hereto; and

(b)   all Proceeds of the foregoing.

3.   SECURITY FOR OBLIGATIONS .  This Patent Security Agreement and the Security Interest created hereby secures the payment and performance of the Secured Obligations, whether now existing or arising hereafter.  Without limiting the generality of the foregoing, this Patent Security Agreement secures the payment of all amounts which constitute part of the Secured Obligations and would be owed by Grantors, or any of them, to Secured Party whether or not they are unenforceable or not allowable due to the existence of an Insolvency Proceeding involving any Grantor.

4.   SECURITY AGREEMENT .  The Security Interest granted pursuant to this Patent Security Agreement is granted in conjunction with the Security Interest granted to Secured Party pursuant to the Security Agreement.  Each Grantor hereby acknowledges and affirms that the rights and remedies of Secured Party with respect to the Security Interest in the Patent Collateral made and granted hereby are more fully set forth in the S