Note 9 - Notes Payable (Details Textual) - USD ($)				1 Months Ended	3 Months Ended		12 Months Ended
	Sep. 30, 2021	Apr. 23, 2021	Apr. 30, 2020	Jan. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2019	Dec. 31, 2017
Long-term Debt, Total					$ 6,921,487	$ 8,622,580	$ 6,921,487	$ 8,622,580
Share Price (in dollars per share)				$ 3.32
Other Income, Paycheck Protection Program Grant								1,048,000
Deferred Other Income Liability						0		0
Conversion of Related Party Debt to Equity [Member]
Debt Conversion, Original Debt, Amount				$ 600,000
Debt Conversion, Converted Instrument, Shares Issued (in shares)				181,000
John H Schwan [Member]
Due to Related Parties, Total					1,175,361	1,123,769	1,175,361	1,123,769
Term Loan [Member]
Long-term Debt, Total					559,140	2,156,895	559,140	2,156,895
Interest Payable					714,094		714,094
Debt Issuance Costs, Net, Total					154,951		154,951
Line of Credit [Member] | Revolving Credit Facility [Member]
Long-term Debt, Total					5,002,599	5,341,916	5,002,599	5,341,916
Promissory Note [Member] | John H Schwan [Member]
Due to Related Parties, Noncurrent, Total				$ 997,019					$ 1,600,000
Repayments of Related Party Debt							0	0
Interest Expense, Related Party					17,000	$ 16,000	70,000	$ 65,000
Promissory Note [Member] | Alex Feng [Member]
Due to Related Parties, Noncurrent, Total					$ 166,667		$ 166,667
Debt Instrument, Interest Rate, Stated Percentage					3.00%		3.00%
Line Financial Agreement [Member]
Debt Instrument, Number of Installments for Periodic Payment	48
Debt Instrument, Periodic Payment, Total	$ 15,234
Debt Instrument, Collateral Monitoring Fee, Percent	4.62%
Debt Instrument, Fee Amount, Percent	1.25%
Debt Instrument, Extension Term (Year)	1 year
Debt Instrument, Renewal Fee, Percent	1.25%
Debt Instrument, Covenant, Tangible Net Worth	$ 4,000,000
Line Financial Agreement [Member] | Maximum [Member]
Debt Instrument, Covenant, Expenditures Amount	$ 1,000,000
Line Financial Agreement [Member] | Prime Rate [Member]
Debt Instrument, Reference Rate	3.25%
Debt Instrument, Basis Spread on Variable Rate	1.95%
Paycheck Protection Program CARES Act [Member]
Proceeds from Issuance of Debt			$ 1,047,700
PNC [Member] | PNC Agreements [Member]
Debt Instrument, Forbearance Fee	$ 250,000	$ 1,000,000
Debt Instrument, Increase (Decrease) in Forbearance Fee if Equity Issuance Occurs		(250,000)
Debt Instrument, Forbearance Fee if Equity Issuance Occurs		750,000
Debt Instrument, Increase (Decrease) in Forbearance Fee if Full Cash Payments Received		(500,000)
Debt Instrument, Forbearance Fee if Full Cash Payments Received		250,000
Forbearance Expense							$ 250,000
PNC [Member] | PNC Agreements [Member] | Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity										$ 18,000,000
PNC [Member] | PNC Agreements [Member] | Term Loan [Member]
Debt Instrument, Face Amount										$ 6,000,000
Long-term Debt, Total		$ 2,000,000
Line Financial [Member] | Line Financial Agreement [Member] | Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	6,000,000
Line Financial [Member] | Line Financial Agreement [Member] | Term Loan [Member]
Debt Instrument, Face Amount	$ 731,250