Note 9 - Share-based Compensation (Tables)

6 Months Ended

Jun. 30, 2017

Notes Tables

Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]

			Weighted
			average
			grant date
	Number of		fair value
	shares		per share
Balance, December 31, 2016		—
RSUs granted		1,176,000	$	0.73
RSUs vested		—
RSUs forfeited		—
Balance, June 30, 2017		1,176,000	$	0.73

Schedule of Share-based Compensation, Expense [Table Text Block]

	Three Months ended June 30,				Six Months ended June 30,
	2017		2016		2017		2016
Cost of goods sold	$	33	$	—	$	74	$	1
Research and development		154		—		326		1
Selling, general and administrative		489		28		898		56
Share-based compensation expense	$	676	$	28	$	1,298	$	58

Share-based Compensation, Stock Options, Activity [Table Text Block]

	Options outstanding
				Weighted
				average
	Number of			exercise
	shares			price
Balance, December 31, 2016		41,903,728		$	0.15
Stock options granted		6,714,410			0.73
Stock options exercised		(107,153	)		0.20
Stock options cancelled		(407,382	)		0.04
Balance, June 30, 2017		48,103,603		$	0.23

Non-employee Stock Options [Member]

Notes Tables

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

Risk-free interest rate	2.25	–	2.28%
Volatility		87%
Dividend yield		None
Expected terms (in years)	9.1	–	9.5

Employee Stock Option [Member]

Notes Tables

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

Risk-free interest rate	1.88	–	2.12%
Volatility	85	–	89%
Dividend yield		None
Expected terms (in years)	5.50	–	6.25