Note 10—Stock-Based Awards

The Company’s Amended and Restated 2006 Equity Incentive Plan (the “Amended 2006 Plan”) provides for broad-based equity grants to its employees and non-employee service providers. The Company also periodically grants equity-based awards outside the Amended 2006 Plan to certain new hires as an inducement to enter into employment with the Company. Subject to certain adjustments, as of December 28, 2019, the Company was authorized to issue a maximum of 13,805,566 shares of its common stock pursuant to awards granted under the Amended 2006 Plan. Pursuant to the terms of the Amended 2006 Plan, beginning January 1, 2017, the automatic annual increase to the number of shares of common stock that may be issued pursuant to awards granted under the Amended 2006 Plan is equal to the lesser of (i) 2.5% of the number of shares of common stock issued and outstanding as of the first day of the applicable calendar year, and (ii) 1,200,000 shares of common stock, subject to adjustment for certain corporate actions. As of December 28, 2019, the Company had 1,101,572 shares of common stock available for issuance pursuant to future awards to be granted under the Amended 2006 Plan.

Stock Options

Stock options granted under the Amended 2006 Plan generally vest at a rate of at least 25% per year over four years and expire 10 years from the date of grant. The weighted-average assumptions used in the Black-Scholes option pricing model and the resulting weighted-average grant date fair value of stock options granted were as follows:


	Year Ended
	December 28,			December 29,
	2019			2018
Expected term (in years)		6.06			6.20
Expected volatility		108	%		108	%
Risk-free interest rate		1.92	%		2.75	%
Expected dividends	$	—		$	—
Weighted-average grant date fair value per share	$	0.29		$	0.21

The following table summarizes the activity related to stock options during the year ended December 28, 2019:


					Weighted-
					Average
			Weighted-		Remaining		Aggregate
	Number of		Average		Contractual		Intrinsic
	Shares		Exercise		Life		Value
	(in thousands)		Price		(in years)		(in thousands)
Outstanding at December 29, 2018		8,186	$	1.18		5.88	$	223
Granted		790	$	0.35
Exercised		(175)	$	0.28
Expired or forfeited		(1,444)	$	0.89
Outstanding at December 28, 2019		7,357	$	1.17		5.54	$	127
Exercisable at December 28, 2019		5,799	$	1.37		4.69	$	49
Vested and expected to vest at December 28, 2019		7,097	$	1.20		5.41	$	114

There was no significant intrinsic value of options exercised during the years ended December 28, 2019 and December 29, 2018.

Restricted Stock Awards and Restricted Stock Units

RSAs granted under the Amended 2006 Plan vest annually on each anniversary of the grant date over a two-year term. RSUs granted for employees and consultants generally vest semi-annually from the grant date over a four-year term, and RSUs granted for independent directors fully-vest on the grant date. The following table summarizes the activity related to RSAs and RSUs during the year ended December 28, 2019:


			Weighted-
			Average
	Number of		Grant-Date
	Shares		Fair Value
	(in thousands)		per Share
Balance nonvested at December 29, 2018		525	$	0.25
Granted		3,727	$	0.55
Vested		(1,012)	$	0.47
Forfeited		(174)	$	0.54
Balance nonvested at December 28, 2019		3,066	$	0.52

Stock-Based Compensation

The following table summarizes the stock-based compensation expense by line item in the consolidated statements of operations (in thousands):


	Year Ended
	December 28,		December 29,
	2019		2018
Cost of sales	$	26	$	26
Research and development		213		236
Selling, general and administrative		750		475
Total	$	989	$	737

As of December 28, 2019, the Company had approximately $1.6 million, net of estimated forfeitures, of unearned stock-based compensation, which it expects to recognize over a weighted-average period of approximately 2.9 years.