Exhibit 5.1

June 25, 2018

Akoustis Technologies, Inc.

Akoustis, Inc.

9805 Northcross Center Court, Suite A

Huntersville, NC 28078

Ladies and Gentlemen:

We have acted as special counsel to Akoustis Technologies, Inc., a Delaware corporation (the “Company”), and Akoustis, Inc., a Delaware corporation (the “Initial Guarantor”), in connection with the Registration Statement on Form S-1 (the “Registration Statement”) filed on the date hereof with the Securities and Exchange Commission under the Securities Act of 1933, as amended (the “Securities Act”), to register:

The Securities were sold pursuant to that certain Purchase Agreement, dated as of May 10, 2018, by and among the Company, the Initial Guarantor and Oppenheimer & Co. Inc., as representative of the several initial purchasers named therein (the “Purchase Agreement”), and issued pursuant to that certain indenture (the “Indenture”) dated May 14, 2018 by and among the Company, the Initial Guarantor and the Bank of New York Mellon Trust Company, N.A., as trustee (the “Trustee”).

K&L Gates LLP

Hearst Tower 47th Floor 214 North Tryon Street Charlotte NC 28202

T +1 704 331 7400 F +1 704 331 7598 klgates.com

Akoustis Technologies, Inc.

Akoustis, Inc.

June 25, 2018

Page 2

You have requested our opinion as to the matters set forth below in connection with the Registration Statement. For purposes of rendering that opinion, we have examined the Registration Statement, the Company’s certificate of incorporation and its bylaws, the Initial Guarantor’s certificate of incorporation and its bylaws, the Purchase Agreement, the Indenture (including the Note Guarantee), the Notes (as represented by a global note deposited with the Depository Trust Company) and the corporate actions of the Company’s and the Initial Guarantor’s boards of directors that provide for (i) the execution, delivery and performance of the Purchase Agreement, the Indenture and the issuance of the Securities and the Convertible Note Shares, and (ii) the execution, delivery and performance of the agreements by which the Selling Stockholder Shares were issued, as well as the issuance of the Selling Stockholder Shares, and we have made such other investigation as we have deemed appropriate. We also have assumed that (i) the Company will have sufficient authorized and unissued shares of its Common Stock upon any issuance of Convertible Note Shares, (ii) that the corporate action of the Company authorizing the issuance of the Convertible Note Shares has not been, and will not be, revoked, modified or amended, and (iii) the issuance of the Convertible Note Shares will be noted in the Company’s stock ledger. We have examined and relied upon certificates of public officials and, as to certain matters of fact that are material to our opinions, we have also relied on a certificate of an officer of the Company. In rendering our opinion, we also have made the assumptions that are customary in opinion letters of this kind. We have not verified any of those assumptions.

Our opinions set forth below are limited to the Delaware General Corporation Law and reported judicial decisions interpreting the Delaware General Corporation Law, and, as to the Notes and the Note Guarantee constituting binding obligations of the Company and the Initial Guarantor, respectively, the laws of the State of New York.

Based upon and subject to foregoing, it is our opinion that:

Akoustis Technologies, Inc.

Akoustis, Inc.

June 25, 2018

Page 3

All of our opinions are subject to and limited by (i) the effect of bankruptcy, insolvency, fraudulent conveyance, reorganization, receivership, moratorium or other similar laws relating to or affecting the rights and remedies of creditors or secured parties generally; (ii) the application of general principles of equity (regardless of whether considered in a proceeding in equity or at law), including, without limitation, the possible unavailability of specific performance, injunctive relief or another equitable remedy; (iii) concepts of materiality, reasonableness, good faith and fair dealing; and (iv) public policy against indemnification for violations of securities laws or for losses caused by the indemnified person’s gross negligence or willful misconduct.

We express no opinion with respect to any provision of the Securities that purports to: (a) waive equitable rights, remedies, or defenses; (b) authorize a party to act in its sole discretion or provide that determination by a party is conclusive; (c) require notices, waivers, amendments, modifications or supplements to be made only in writing; (d) effect waivers of statutory or equitable rights or the effect of applicable laws; (e) waive or modify any party’s diligence obligations; (f) impose liquidated damages to the extent constituting a penalty; (g) relieve any party of the consequences of its own unlawful, willful or negligent acts or omissions; (h) grant indemnity or a right of contribution to the extent violating applicable public policy; (i) create rights of setoff or subrogation; (j) impose an increased interest rate, interest on interest, late charge, or any additional obligation or burden upon the occurrence of a default of any obligation thereunder to the extent constituting a penalty; (k) limit or preclude the liability of any party for consequential, special, punitive or indirect damages; (l) permit the declaration of a default for an immaterial breach of provisions thereof; (m) waive the right to trial by jury; (n) designate the jurisdiction, forum or venue for resolution of any cause of action or dispute or the method of service of process; (o) require enforcement of one or more provisions thereof notwithstanding that one or more other provisions thereof may be unenforceable; (p) provide that enumerated remedies are not exclusive or that a party has the right to pursue multiple remedies without regard to other remedies elected or that all remedies are cumulative; (q) establish evidentiary standards by which it is to be construed; (r) permit the exercise, under certain circumstances, of rights without notice or without providing opportunity to cure failures to perform; (s) bind persons that are not party thereto; or (t) grant a power of attorney or proxy.

We also express no opinion as to (i) whether a federal court of the United States outside of the State of New York, a state court outside the State of New York, or a foreign court would give effect to the choice of New York law provided for in the Indenture and the Securities; (ii) whether a federal court of the United States outside the State of New York, or a state court outside the State of New York, would have personal jurisdiction over any party; or (iii) whether a federal court of the United States would have subject matter jurisdiction over any action brought against any party.

Akoustis Technologies, Inc.

Akoustis, Inc.

June 25, 2018

Page 4

Our opinions as to enforceability in numbered paragraphs 1 and 2 above are based on Section 5-1401 of the New York General Obligations Law (“GOL 5-1401”). GOL 5-1401 provides, in pertinent part, that “the parties to any contract . . . may agree that the law of this state shall govern their rights and duties in whole or in part, whether or not such contract, agreement or undertaking bears a reasonable relation to this state.” Although the New York Court of Appeals has recently upheld the application of that statute in IRB-Brasil Resseguros, S.A. v. Inepur Invs., S. A., 82 N.E.2d 609 (N.Y. 2012), we note that legal commentators have questioned the validity thereof under the Constitution of the United States, and we express no opinion as to the constitutionality of such law. We draw your attention to the fact that at least one federal court has, notwithstanding the terms of GOL 5-1401, in dictum noted possible constitutional limitations upon GOL 5-1401, in both domestic and international transactions. See e.g., Lehman Brothers Commercial Corp. v. Minmetals Non-Ferrous Metals Trading Co., No. 94 Civ. 8301, 2000 WL 1702039 S.D.N.Y. Nov. 13, 2000.

With respect to the opinion set forth in numbered paragraph 2, we note that the Note Guarantee purports to waive certain rights and defenses that the Guarantors might otherwise have with respect to, among other things, (a) the validity, regularity or enforceability of the Notes or the Indenture; (b) the absence of any action to enforce the same, any waiver or consent by any holder of the Notes; (c) the recovery of any judgment against the Company; (d) any action to enforce the same; or (e) any other circumstance which might otherwise constitute a legal or equitable discharge or defense of a Guarantor. Although we believe that the provisions of the Note Guarantee are generally enforceable (subject to the limitations and qualifications set forth in this opinion letter), we advise you that certain waivers and other provisions may be further limited or rendered unenforceable by applicable law but that, in our opinion, such law does not render the Note Guarantee invalid as a whole or preclude the judicial enforcement of the Note Guarantee upon a material default by any Guarantor thereunder.

We hereby consent to the filing of this opinion as an exhibit to the Registration Statement and to the reference to this firm in the related prospectus under the caption “Legal Matters.” In giving our consent we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act or the rules and regulations thereunder.