Note 13 - Stockholders' Equity (Tables)
|
12 Months Ended |
Dec. 31, 2020 |
|---|
| Notes Tables |
|
| Schedule of Warrant Valuation Assumptions [Table Text Block] |
| |
|
Veolia Warrant #1 |
|
|
Veolia Warrant #2 |
|
|
Jan. 2019 Offering Underwriter |
|
| Warrant shares issued |
|
|
2,000,000 |
|
|
|
2,000,000 |
|
|
|
103,500 |
|
| Market price |
|
$ |
3.02 |
|
|
$ |
3.02 |
|
|
$ |
2.16 |
|
| Exercise price |
|
$ |
5.00 |
|
|
$ |
7.00 |
|
|
$ |
1.90 |
|
| Term (years) |
|
|
10 |
|
|
|
10 |
|
|
|
5 |
|
| Risk-free interest rate |
|
|
2.64 |
% |
|
|
2.64 |
% |
|
|
2.57 |
% |
| Volatility |
|
|
81.50 |
% |
|
|
81.50 |
% |
|
|
81.00 |
% |
| Dividend rate |
|
|
— |
% |
|
|
— |
% |
|
|
— |
% |
| Per share FV of warrant |
|
$ |
2.35 |
|
|
$ |
2.24 |
|
|
$ |
1.47 |
|
| FV of warrant |
|
$ |
4,699 |
|
|
$ |
4,474 |
|
|
$ |
152 |
|
|
| Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block] |
| |
|
|
|
|
|
|
|
Shares Subject to Purchase |
|
| Exercise Price per Share |
|
|
Expiration Date |
|
|
at December 31, 2020 |
|
| $ |
1.90 |
|
|
|
1/22/2024 |
|
|
|
103,500 |
|
|
| Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] |
| |
|
Year ended December 31, |
|
| |
|
2020 |
|
|
2019 |
|
| Cost of product sales |
|
$ |
90 |
|
|
$ |
357 |
|
| Research and development cost |
|
|
183 |
|
|
|
200 |
|
| General and administrative expense |
|
|
3,296 |
|
|
|
3,649 |
|
| Total |
|
$ |
3,569 |
|
|
$ |
4,206 |
|
|
| Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] |
| |
|
Year ended December 31, |
|
| |
|
2019 |
|
| |
|
|
|
|
| Expected stock volatility |
|
|
82.2 - 87.5 |
% |
| Risk free interest rate |
|
|
1.7 - 2.6 |
% |
| Expected years until exercise |
|
|
1.0 - 4.0 |
|
| Dividend yield |
|
|
— |
% |
|
| Share-based Payment Arrangement, Option and Restricted Stock Unit, Activity [Table Text Block] |
| |
|
|
|
|
|
Options Outstanding |
|
|
RSUs Outstanding |
|
| |
|
|
|
|
|
|
|
|
|
Weighted- |
|
|
|
|
|
|
Weighted- |
|
| |
|
Number of |
|
|
|
|
|
|
Average |
|
|
|
|
|
|
Average |
|
| |
|
Shares |
|
|
|
|
|
|
Exercise |
|
|
|
|
|
|
Grant Date |
|
| |
|
Available for |
|
|
Number of |
|
|
Price Per |
|
|
Number of |
|
|
Fair Value |
|
| |
|
Grant |
|
|
Shares |
|
|
Share |
|
|
RSUs |
|
|
Per Share |
|
| Balance at December 31, 2018 |
|
|
805,749 |
|
|
|
1,694,068 |
|
|
$ |
4.57 |
|
|
|
96,623 |
|
|
$ |
4.01 |
|
| Authorized |
|
|
4,500,000 |
|
|
|
— |
|
|
|
— |
|
|
|
— |
|
|
|
— |
|
| Granted |
|
|
(3,468,296 |
) |
|
|
2,197,074 |
|
|
|
3.19 |
|
|
|
1,271,222 |
|
|
|
1.52 |
|
| Exercised/ Released |
|
|
— |
|
|
|
— |
|
|
|
— |
|
|
|
(970,630 |
) |
|
|
1.63 |
|
| Forfeited |
|
|
564,873 |
|
|
|
(427,450 |
) |
|
|
4.46 |
|
|
|
(137,423 |
) |
|
|
1.85 |
|
| Balance at December 31, 2019 |
|
|
2,402,326 |
|
|
|
3,463,692 |
|
|
$ |
3.71 |
|
|
|
259,792 |
|
|
$ |
1.83 |
|
| Authorized |
|
|
7,000,000 |
|
|
|
— |
|
|
|
— |
|
|
|
— |
|
|
|
— |
|
| Granted |
|
|
(8,056,280 |
) |
|
|
— |
|
|
|
— |
|
|
|
8,056,280 |
|
|
|
0.64 |
|
| Exercised/ Released |
|
|
— |
|
|
|
— |
|
|
|
— |
|
|
|
(2,514,000 |
) |
|
|
0.72 |
|
| Forfeited |
|
|
2,253,925 |
|
|
|
(2,076,019 |
) |
|
|
3.59 |
|
|
|
(177,906 |
) |
|
|
0.50 |
|
| Issued to fulfill obligations for separation agreements |
|
|
(201,101 |
) |
|
|
— |
|
|
|
— |
|
|
|
— |
|
|
|
— |
|
| Balance at December 31, 2020 |
|
|
3,398,870 |
|
|
|
1,387,673 |
|
|
$ |
3.89 |
|
|
|
5,624,166 |
|
|
$ |
0.66 |
|
| |
|
|
|
|
|
Weighted- |
|
|
Weighted- |
|
|
|
|
|
| |
|
|
|
|
|
Average |
|
|
Average |
|
|
|
|
|
| |
|
|
|
|
|
Exercise |
|
|
Remaining |
|
|
Aggregate |
|
| |
|
|
|
|
|
Price Per |
|
|
Contractual |
|
|
Intrinsic Value |
|
| |
|
Shares |
|
|
Share |
|
|
Life (Years) |
|
|
(in thousands) |
|
| Outstanding |
|
|
1,387,673 |
|
|
$ |
3.89 |
|
|
|
1.98 |
|
|
$ |
434 |
|
| Vested and exercisable |
|
|
1,068,284 |
|
|
$ |
3.80 |
|
|
|
1.85 |
|
|
$ |
400 |
|
|
| Share-based Payment Arrangement, Option, Exercise Price Range [Table Text Block] |
| |
|
Options Outstanding |
|
|
Options Exercisable |
|
| |
|
|
|
|
|
Weighted- |
|
|
|
|
|
|
Weighted- |
|
| |
|
|
|
|
|
Average |
|
|
|
|
|
|
Average |
|
| |
|
|
|
|
|
Remaining |
|
|
|
|
|
|
Remaining |
|
| |
|
|
|
|
|
Contractual |
|
|
|
|
|
|
Contractual |
|
| |
|
Number of |
|
|
Life |
|
|
Number of |
|
|
Life |
|
| Range of Exercise Prices |
|
Shares |
|
|
(Years) |
|
|
Shares |
|
|
(Years) |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1.600 -2.5050 |
|
|
414,159 |
|
|
|
1.22 |
|
|
|
375,270 |
|
|
|
1.05 |
|
| 2.511 -3.1414 |
|
|
422,833 |
|
|
|
2.34 |
|
|
|
282,333 |
|
|
|
2.34 |
|
| 3.155 -3.8686 |
|
|
17,482 |
|
|
|
4.33 |
|
|
|
17,482 |
|
|
|
4.33 |
|
| 3.877 -4.6464 |
|
|
69,485 |
|
|
|
2.34 |
|
|
|
69,485 |
|
|
|
2.34 |
|
| 4.655 -16.5454 |
|
|
463,714 |
|
|
|
2.19 |
|
|
|
323,714 |
|
|
|
2.12 |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
1,387,673 |
|
|
|
1.98 |
|
|
|
1,068,284 |
|
|
|
1.85 |
|
|
| Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] |
| |
|
Number of Shares |
|
| Equity Plan |
|
|
|
|
| Subject to outstanding options and restricted shares |
|
|
7,011,839 |
|
| Available for future grants |
|
|
3,398,870 |
|
| Officer and Director Purchase Plan |
|
|
237,382 |
|
| Warrants |
|
|
103,500 |
|
| |
|
|
10,751,591 |
|
|