Nature of the business and basis of presentation (Details)					3 Months Ended		6 Months Ended
	Apr. 28, 2021 USD ($) shares	Oct. 13, 2020 USD ($) $ / shares	Oct. 13, 2020 $ / shares shares	Oct. 06, 2020 $ / shares shares	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Apr. 28, 2021 shares	Apr. 28, 2021 $ / shares	Apr. 28, 2021 item	Dec. 31, 2020 USD ($)
Net loss					$ (5,241,000)	$ (2,710,000)	$ (9,139,000)	$ (5,387,000)
Accumulated deficit					(63,533,000)		(63,533,000)					$ (54,394,000)
Proceeds from issuance of common stock		$ 41,700,000					906,000
Payments of underwriting discounts and commissions		$ 3,100,000
Cash					$ 59,800,000		$ 59,800,000
IPO
Stock issued | shares				3,250,000
Share price | $ / shares				$ 12.00
Over-Allotment Option
Stock issued | shares			487,500
Share price | $ / shares		$ 12.00	$ 12.00
Private offering
Share price | $ / shares										$ 27.00
Proceeds from issuance of common stock	$ 27,000,000.0
Net proceeds from issuance of common stock	$ 26,400,000
Number of units issued | shares	1,000,000
Number of share for company's common stock	1										1
Number of warrants | shares									1