<PAGE>
                                                                    Exhibit 4.1

                             MUSI INVESTMENTS S.A.

                          CONVERTIBLE PROMISSORY NOTE


<TABLE>

<S>                                                                              <C>
This  Note  is  entered   into  June  7,  2002  to  be                           Maturity Date June 3, 2004
effective as of June 3, 2002  (References  to the date
of this Note contained  herein shall be deemed to mean
June 3, 2002.)
</TABLE>

<TABLE>
<CAPTION>
===================================================================================================================
Lender:                                                                    Borrower:
<S>                                                                        <C>

MUSI Investments S.A.                                             Frisby Technologies, Inc.
231 Val des Bons Malades                                          3195 Centre Park Blvd.
L-2121 Luxembourg-Kirchberg                                       Winston-Salem, NC County: Forsyth 27107

===================================================================================================================
</TABLE>

         FOR VALUE RECEIVED, the undersigned Borrower unconditionally promises
to pay to the order of Lender, its successors and assigns, without setoff, at
its offices indicated at the beginning of this Note, or at such other place as
may be designated by Lender, the principal amount of up to Three Hundred
Thousand and 00/100 Dollars ($300,000.00), or so much thereof as may be
advanced from time to time in immediately available funds, together with
interest computed daily on the outstanding principal balance hereunder, at an
annual interest rate, and in accordance with the payment schedule, indicated
below.

1.       RATE.  The Rate shall be the Prime Rate plus 0.75%.

The "Prime Rate" is the so-called composite "Prime Rate" which is published
from time to time during the relevant period in the Southeast Edition of The
Wall Street Journal listing of "Money Rates" and shall be the arithmetic
average of such published rates if more than one is quoted.

Notwithstanding any provision of this Note, Lender does not intend to charge
and Borrower shall not be required to pay any amount of interest or other
charges in excess of the maximum permitted by the applicable law of the State
of North Carolina; if any higher rate ceiling is lawful, then that higher rate
ceiling shall apply. Any payment in excess of such maximum shall be refunded to
Borrower or credited against principal, at the option of Lender.

2.       ACCRUAL METHOD. Unless otherwise indicated, interest at the Rate set
forth above will be calculated by the 365/360 day method (a daily amount of
interest is computed for a hypothetical year of 360 days; that amount is
multiplied by the actual number of days for which any principal is outstanding
hereunder).

3.       RATE CHANGE DATE. Any Rate based on a fluctuating index or base rate
will change, unless otherwise provided, each time and as of the date that the
index or base rate changes. In the event The Wall Street Journal ceases to
publish the Prime Rate, Lender shall substitute an index determined by Lender
to be comparable, in its sole discretion.

4.       PAYMENT SCHEDULE. All payments received hereunder shall be applied
first to the payment of any expense or charges payable hereunder or under any
other loan documents executed in connection with this Note, then to interest
due and payable, with the balance applied to principal, or in such other order
as Lender shall determine at its option.

Single Principal Amount. Unless Lender exercises its rights under Section 5 as
to the entire principal balance of this Note, principal shall be paid in full
in a single payment on June 3, 2004 (the "Maturity Date"). Interest thereon
shall be paid on a quarterly basis beginning with the quarter ending June 30,
2002 with such payments being due on the first business day after the end of
each successive quarter. Each payment shall be accompanied by a statement from
Borrower setting forth in reasonable detail the interest then due and payable
for such quarter. Unless Lender exercises its rights under Section 5 as to such
amounts, a final payment of all accrued and unpaid interest shall be made on
the Maturity Date.


<PAGE>

5        CONVERSION AND PURCHASE.

         (a)      At any time on or prior to the Maturity Date, Lender shall
have the right, subject to the terms of this Note, to convert the outstanding
principal balance and any accrued and unpaid interest due under this Note, or a
portion thereof, into a number of shares of the common stock of the Borrower
("Common Stock") determined as provided in Section 5(b) (the "Conversion
Shares"). Upon conversion of the full principal amount and all accrued and
unpaid interest of this Note, this Note will be discharged in full. In order to
exercise the conversion right referred to in this Section 5, Lender shall
surrender this Note to the Borrower at its principal office together with the
completed Conversion Form attached hereto as Exhibit A (the "Conversion Form").
Upon such surrender, the Borrower shall issue a certificate or certificates in
the name of Lender for the largest number of whole shares of Common Stock to
which Lender shall be entitled and, if this Note is converted in whole, in lieu
of any fractional share of the Common Stock to which the Lender shall be
entitled, cash equal to remaining unconverted balance.

         (b)      Subject to Section 5(e), the number of Conversion Shares into
which this Note is convertible shall be determined by dividing the portion of
the unpaid principal amount and accrued and unpaid interest of the Note being
converted by the "Conversion Price." The "Conversion Price" shall be the lesser
of (i) the 30-day trailing average closing trading price of the Common Stock on
the NASDAQ Stock Market as of the date that the conversion is deemed to have
been made as provided in Section 5(c) (the "Conversion Date") or, if the
Borrower's is not then listed on NASDAQ, the fair market value of the Common
Stock as of the Conversion Date as determined in good faith by Borrower's Board
of Directors, or (ii) the then effective "Purchase Price" as defined in the
Stock Purchase Warrants issued in January 2002 to DAMAD Holding AG and Bluwat
AG (the "Outstanding Warrants") or, if each of the Outstanding Warrants has
been exercised in full or has expired unexercised, the Purchase Price at the
time of the last such exercise or expiration.

         (c)      Subject to the provisions of this Section 5, any such
conversion shall be deemed to have been made at the close of business on the
date that this Note shall have been surrendered for conversion together with
the Conversion Form, so that the rights of the Lender as a holder of this Note
shall cease at such time and the person or persons entitled to receive the
Conversion Shares upon conversion of this Note shall be treated for all
purposes as having become record holder or holders of such Conversion Shares at
such time and such conversion shall be at the Conversion Price in effect at
such time. Notwithstanding the foregoing, no such surrender on any date when
the stock transfer books of the Borrower shall be closed shall be effective to
constitute the person or persons entitled to receive the Conversion Shares upon
such conversion as the record holder or holders of such Conversion Shares on
such date, but such surrender shall be effective to constitute the person or
persons entitled to receive such Conversion Shares as the record holder or
holders thereof for all purposes at the close of business on the next
succeeding day on which such stock transfer books are open and such conversion
shall be at the Conversion Price in effect at the close of business on such
next succeeding day. If the last day for the exercise of the conversion rights
shall not be a business day, then such conversion right may be exercised on the
next succeeding business day.

         (d)      Subject to Section 5(e), on or before the Maturity Date,
Lender shall have the right and option to purchase up to an aggregate number of
shares of Common Stock equal to (i) the positive excess, if any, of (A)
$300,000.00 over (B) the aggregate principal amount theretofore converted or
thereafter convertible pursuant to Section 5(a), divided by (ii) the Conversion
Price. In connection with any such purchase, Lender agrees to deliver to
Borrower customary investor representations and warranties including to the
effect that Lender is an "accredited investor" as defined under Rule 501
promulgated under the Securities Act of 1933, as amended.

         (e)      Notwithstanding anything contained herein to the contrary,
the maximum number of shares of Common Stock for which this Note may be
converted and which may be purchased in accordance with Section 5(d), together,
shall not exceed in the aggregate 1,764,347 (which is 19.9% of the number of
shares of Common Stock outstanding as of the date of this Note), as adjusted
for stock splits, reverse stock splits, reclassifications and other similar
changes affecting the Common Stock.

6.       WAIVERS, CONSENTS AND COVENANTS. Borrower, any endorser, or guarantor
hereof or any other party hereto (individually an "Obligor" and collectively
"Obligors") and each of them jointly and severally: (a) waive presentment,
demand, protest, notice of demand, notice of intent to accelerate, notice of
acceleration of maturity, notice of protest, notice of nonpayment, notice of
dishonor, and any other notice (excluding notices to be given under the Loan
Agreement) required to be given under the law to any Obligor in connection with
the delivery, acceptance, performance, default or enforcement of this Note, any
endorsement or guaranty of this Note, or any other documents executed in
connection with this Note or any other note or other loan documents now or
hereafter executed in connection with any obligation of Borrower to Lender (the
"Loan Documents"); (b) consent to all delays, extensions or renewals of this
Note or the Loan Documents, or waivers of any term hereof or of the Loan
Documents, or release or discharge by Lender of any of Obligors, or release,
substitution or exchange of any security for the payment hereof,


                                       2
<PAGE>

or the failure to act on the part of Lender, or any indulgence shown by Lender
(without notice to or further assent from any of Obligors), and agree that no
such action, failure to act or failure to exercise any right or remedy by
Lender shall in any way affect or impair the obligations of any Obligors or be
construed as a waiver by Lender of, or otherwise affect, any of Lender's rights
under this Note, under any endorsement or guaranty of this Note or under any of
the Loan Documents; and (c) agree to pay, on demand, all reasonable costs and
expenses of collection or defense of this Note or of any endorsement or
guaranty hereof and/or the enforcement or defense of Lender's rights with
respect to, or the administration, supervision, preservation, protection of, or
realization upon, any property securing payment hereof, including, without
limitation, reasonable attorney's fees, including fees related to any suit,
mediation or arbitration proceeding, out of court payment agreement, trial,
appeal, bankruptcy proceedings or other proceeding, provided such costs, fees
and expenses shall not exceed 15% of the obligations due hereunder.

7.       PREPAYMENTS. Prepayments may be made in whole or in part at any time.
The Borrower may reborrow any prepayments of principal at any time up to the
maximum available under the Note.

8.       DELINQUENCY CHARGE. To the extent permitted by law, a delinquency
charge may be imposed in an amount not to exceed three percent (3.0%) of the
unpaid portion of any payment that is more than fifteen days late. Unless the
terms of this Note call for repayment of the entire balance of this Note (both
principal and interest) in a single payment and not for installments of
interest or principal and interest, the 3.0% delinquency charge may be imposed
not only with respect to regular installments of principal or interest or
principal and interest, but also with respect to any other payment in default
under this Note (other than a previous delinquency charge), including without
limitation a single payment of principal due at the maturity of this Note. In
the event any installment, or portion thereof, is not paid in a timely manner,
subsequent payments will be applied first to the past due balance (which shall
not include any previous delinquency charges), specifically to the oldest
maturing installment, and a separate delinquency charge will be imposed for
each payment that becomes due until the default is cured.

9.       EVENTS OF DEFAULT. The occurrence of a "Default" under Section 8 of
the Loan Agreement shall constitute an event of default hereunder (an "Event of
Default").

10.      REMEDIES UPON DEFAULT. Whenever there is an Event of Default under
this Note (a) the entire balance outstanding hereunder and all other
obligations of any Obligor to Lender (however acquired or evidenced) shall, at
the option of Lender, become immediately due and payable and any obligation of
Lender to permit further borrowing under this Note shall immediately cease and
terminate, and/or (b) to the extent permitted by law, the Rate of interest on
the unpaid principal shall be increased at Lender's discretion up to the
maximum rate allowed by law, or if none, a per annum rate of interest equal to
the Prime Rate plus 3.75% (the "Default Rate"). The provisions herein for a
Default Rate and a delinquency charge shall not be deemed to extend the time
for any payment hereunder or to constitute a "grace period" giving Obligors a
right to cure any default. At Lender's option, any accrued and unpaid interest,
fees or charges may, for purposes of computing and accruing interest on a daily
basis after the due date of the Note or any installment thereof, be deemed to
be a part of the principal balance, and interest shall accrue on a daily
compounded basis after such date at the Default Rate provided in this Note
until the entire outstanding balance of principal and interest is paid in full.
Lender is hereby authorized at any time to set off and charge against any
deposit accounts of any Obligor, as well as any money, instruments, securities,
documents, chattel paper, credits, claims, demands, income and any other
property, rights and interests of any Obligor which at any time shall come into
the possession or custody or under the control of Lender or any of its agents,
affiliates or correspondents, without notice or demand, any and all obligations
due hereunder. Additionally, Lender shall have all rights and remedies
available under each of the Loan Documents, as well as all rights and remedies
available at law or in equity.

11.      NON-WAIVER. The failure at any time of Lender to exercise any of its
options or any other rights hereunder shall not constitute a waiver thereof,
nor shall it be a bar to the exercise of any of its options or rights at a
later date. All rights and remedies of Lender shall be cumulative and may be
pursued singly, successively or together, at the option of Lender. The
acceptance by Lender of any partial payment shall not constitute a waiver of
any default or of any of Lender's rights under this Note. No waiver of any of
its rights hereunder, and no modification or amendment of this Note, shall be
deemed to be made by Lender unless the same shall be in writing, duly signed on
behalf of Lender; each such waiver shall apply only with respect to the
specific instance involved, and shall in no way impair the rights of Lender or
the obligations of Obligor to Lender in any other respect at any other time,

12.      APPLICABLE LAW, VENUE AND JURISDICTION. This Note and the rights and
obligations of Borrower and Lender shall be governed by and interpreted in
accordance with the law of the State of North Carolina. In any litigation in
connection with or to enforce this Note or any endorsement or guaranty of this
Note or any Loan Documents, Obligors, and each of them, irrevocably consent to
and confer personal jurisdiction on the courts of the State of North Carolina
or the United States located within the State of North Carolina and expressly
waive any objections as to venue in any such courts. Nothing contained herein
shall, however, prevent Lender from bringing


                                       3
<PAGE>

any action or exercising any rights within any other state or jurisdiction or
from obtaining personal jurisdiction by any other means available under
applicable law.

13.      PARTIAL INVALIDITY. The unenforceability or invalidity of any
provision of this Note shall not affect the enforceability or validity of any
other provision herein and the invalidity or unenforceability of any provision
of this Note or of the Loan Documents to any person or circumstance shall not
affect the enforceability or validity of such provision as it may apply to
other persons or circumstances.

14.      BINDING EFFECT. This Note shall be binding upon and inure to the
benefit of Borrower, Obligors and Lender and their respective successors,
assigns, heirs and personal representatives, provided, however, that no
obligations of Borrower or Obligors hereunder can be assigned without prior
written consent of Lender.

15.      CONTROLLING DOCUMENT. To the extent that this Note conflicts with or
is in any way incompatible with any other Loan Document concerning this
obligation, the Note shall control over any other document, and if the Note
does not address an issue, then each other document shall control to the extent
that it deals most specifically with an issue,

16.      ARBITRATION. ANY CONTROVERSY OR CLAIM BETWEEN OR AMONG THE PARTIES
HERETO INCLUDING BUT NOT LIMITED TO THOSE ARISING OUT OF OR RELATING TO THIS
INSTRUMENT, AGREEMENT OR DOCUMENT OR ANY RELATED INSTRUMENTS, AGREEMENTS OR
DOCUMENTS, INCLUDING ANY CLAIM BASED ON OR ARISING FROM AN ALLEGED TORT, SHALL
BE DETERMINED BY BINDING ARBITRATION IN ACCORDANCE WITH THE FEDERAL ARBITRATION
ACT (OR IF NOT APPLICABLE, THE APPLICABLE STATE LAW), THE RULES OF PRACTICE AND
PROCEDURE FOR THE ARBITRATION OF COMMERCIAL DISPUTES OF AMERICAN ARBITRATION
ASSOCIATION OR ANY SUCCESSOR THEREOF ("A.A.A."), AND THE "SPECIAL RULES" SET
FORTH BELOW. IN THE EVENT OF ANY INCONSISTENCY, THE SPECIAL RULES SHALL
CONTROL. JUDGMENT UPON ANY ARBITRATION AWARD MAY BE ENTERED IN ANY COURT HAVING
JURISDICTION. ANY PARTY TO THIS INSTRUMENT, AGREEMENT OR DOCUMENT MAY BRING AN
ACTION, INCLUDING A SUMMARY OR EXPEDITED PROCEEDING, TO COMPEL ARBITRATION OF
ANY CONTROVERSY OR CLAIM TO WHICH THIS AGREEMENT APPLIES IN ANY COURT HAVING
JURISDICTION OVER SUCH ACTION.

         A.       SPECIAL RULES. THE ARBITRATION SHALL BE CONDUCTED IN FORSYTH
COUNTY, NORTH CAROLINA, AND ADMINISTERED BY A.A.A. WHO WILL APPOINT AN
ARBITRATOR. ALL ARBITRATION HEARINGS WILL BE COMMENCED WITHIN 90 DAYS OF THE
DEMAND FOR ARBITRATION; FURTHER, THE ARBITRATOR SHALL ONLY, UPON A SHOWING OF
CAUSE, BE PERMITTED TO EXTEND THE COMMENCEMENT OF SUCH HEARING FOR UP TO AN
ADDITIONAL 60 DAYS.

         B.       RESERVATION OF RIGHTS. NOTHING IN THIS ARBITRATION PROVISION
SHALL BE DEEMED TO (I) LIMIT THE APPLICABILITY OF ANY OTHERWISE APPLICABLE
STATUTES OF LIMITATION OR REPOSE AND ANY WAIVERS CONTAINED IN THIS INSTRUMENT,
AGREEMENT OR DOCUMENT; OR (II) LIMIT THE RIGHT OF LENDER HERETO (A) TO EXERCISE
SELF HELP REMEDIES SUCH AS (BUT NOT LIMITED TO) SETOFF, OR (B) TO FORECLOSE
AGAINST ANY REAL OR PERSONAL PROPERTY COLLATERAL, OR (C) TO OBTAIN FROM A COURT
PROVISIONAL OR ANCILLARY REMEDIES SUCH AS (BUT NOT LIMITED TO) INJUNCTIVE
RELIEF, WRIT OF POSSESSION OR THE APPOINTMENT OF A RECEIVER. LENDER MAY
EXERCISE SUCH SELF HELP RIGHTS, FORECLOSE UPON SUCH PROPERTY, OR OBTAIN SUCH
PROVISIONAL OR ANCILLARY REMEDIES BEFORE, DURING OR AFTER THE PENDENCY OF ANY
ARBITRATION PROCEEDING BROUGHT PURSUANT TO THIS INSTRUMENT, AGREEMENT OR
DOCUMENT. NEITHER THIS EXERCISE OF SELF HELP REMEDIES NOR THE INSTITUTION OR
MAINTENANCE OF AN ACTION FOR FORECLOSURE OR PROVISIONAL OR ANCILLARY REMEDIES
SHALL CONSTITUTE A WAIVER OF THE RIGHT OF ANY PARTY, INCLUDING THE CLAIMANT IN
ANY SUCH ACTION, TO ARBITRATE THE MERITS OF THE CONTROVERSY OR CLAIM
OCCASIONING RESORT TO SUCH REMEDIES.

BORROWER REPRESENTS TO LENDER THAT THE PROCEEDS OF THIS LOAN ARE TO BE USED
EXCLUSIVELY FOR BUSINESS PURPOSES. BORROWER ACKNOWLEDGES HAVING READ AND
UNDERSTOOD, AND AGREES TO BE BOUND BY, ALL TERMS AND CONDITIONS OF THIS NOTE
AND HEREBY EXECUTES THIS NOTE UNDER SEAL AS OF THE DATE HERE ABOVE WRITTEN.


                                       4
<PAGE>

NOTICE OF FINAL AGREEMENT. THIS WRITTEN PROMISSORY NOTE REPRESENTS THE FINAL
AGREEMENT BETWEEN THE PARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR,
CONTEMPORANEOUS, OR SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO
UNWRITTEN ORAL AGREEMENTS BETWEEN THE PARTIES.



FRISBY TECHNOLOGIES, INC.

By: /s/Gregory S. Frisby (Seal)
    --------------------
Name:    Gregory S. Frisby
Title:   Chairman and CEO



/s/ John L. Ruggiero
------------------------
Attest (If Applicable)
[Corporate Seal]


                                       5
<PAGE>

                                   EXHIBIT A

                                CONVERSION FORM


FRISBY TECHNOLOGIES, INC.

                  The undersigned, MUSI INVESTMENTS S.A., pursuant to the
provisions of the within Note, hereby elects to convert $________________ of
the unpaid principal amount and/or accrued and unpaid interest of such Note
into the number of Conversion Shares of Frisby Technologies, Inc. into which
such amount is convertible at the Conversion Price. The Conversion Shares shall
be registered in the name of MUSI Investments S.A. whose address is 231 Val des
Bons Malades, L-2121 Luxembourg-Kirchberg.


Dated:______________

                                             MUSI INVESTMENTS S.A.

                                             -----------------------------------
                                             Signature



                                             -----------------------------------
                                             Address



                                             -----------------------------------

                                       6