ike her life--has always teetered between science and art.

It was art that the Swiss-born Lili-Charlotte Sarnoff (nee Dreyfus) had studied in Berlin and Florence before immigrating to America in 1940. But her marriage to an American surgeon set her inventive imagination on a different tack: Working as a research assistant at the Harvard School of Public Health and later at the National Institutes of Health, she coauthored, with her husband, several articles on polio and pulmonary edema, and helped devise -- among other mechanical wonders -- a new kind of respirator for bulbar polio victims.

She still chuckles with pride at having been listed, in 1960, in "American Men of Science" -- since renamed "American Men and Women of Science."

Sarnoff's return to art came almost by accident in 1968. While organizing a light show for children at the Corcoran, she was offered a hank of optical fibers -- limp, hairlike filaments that, when lit at one end, conduct light to a glowing tip at the other end. Her first sculptures grew out of a search for ways to exhibit the intriguing new stuff; later she began to display the new filament by sandwiching it between layers of clear Plexiglas cut into curvaceous, flame-like forms. The sculptures that grew from these experiments--there are examples at the Kennedy Center, the Air and Space Museum and the Corning Museum of Glass -- became her hallmark.

Mesmerizing as they were, these works remained, for some of us, essentially decorative objects--expensive toys that seemed more gimmicky as plug-in objets began to proliferate in places like Brentano's and neighborhood drugstores. To her great credit, Sarnoff seems to have confronted that problem, and her new show at Gallery K has not a single electrical plug or optical fiber in sight. It is her strongest show to date.

These small, handsomely mounted trios of perforated circles, triangles, teardrops and leaf shapes cut from Plexiglas retain the elegance of the earlier work, but gain from Sarnoff's apparent new confidence to explore pure sculptural form, leaving the gee-whiz technological crutch behind. "Avenue of the Morning Light" is typical: three flame-like forms of increasing size, laid out along the lines of a geometric projection. Had the works been properly installed -- above the normal sight line -- they could be seen to merge into concentric constellations, a subtlety that may otherwise be overlooked.

Best of all are the more free-form, gestural works such as "Serendipity" and "On the Strip," where science is abandoned altogether and Sarnoff, at last, settles down to making pure art. The show continues at 2032 P St. NW through Dec. 4. Hours are Tuesdays through Fridays, 11 to 6. Olivier Debre at Gallery K

Also on view at Gallery K are new oils by Frenchman Olivier Debre, who made good abstractions back in the '50s (the Phillips has one), but currently seems to be preoccupied with an attempt to combine stain painting and Abstract Expressionism into something new. It doesn't work.

Debre begins by aping Morris Louis, covering large, prepared canvases with poured oil paint, thinned to a wash with turpentine. He then attempts to liven up these uneventful fields by adding thick swaths of Abstract Expressionist gestures, laid on with a palette knife. That doesn't work either. In the end, these are vacuous abstractions with not even attractive color to recommend them.

This show also continues through Dec. 4. Paper-Makers at IMF

Paper-making has captured the imagination of many good artists in recent years, among them painters like Kenneth Noland (now showing handmade paperworks at Kornblatt Gallery) and sculptors like Washington's own Hilda Thorpe, Sirpa Yarmolinsky and Yuriko Yamaguchi, the stars of "Paper as an Art Form" at the International Monetary Fund gallery, 700 19th St. NW.

Though the title overreaches the effort, the show is well worth seeing if you're in the neighborhood -- or if you're mad for handmade paper. There are highly sculptural works -- like Hilda Thorpe's large-scale swath of cheesecloth and white pulp, Yarmolinsky's dramatic tar-paper constructions and Yamaguchi's handsome wall reliefs. And there are some equally wonderful, more intimate pieces by artists we have not seen before -- notably Helen C. Frederick of Baltimore. The focus gets a bit fuzzy, but the common denominator here seems to be that all these artists take their paper-making seriously.

Organized by Frederick, an artist and paper-maker who directs Baltimore's nonprofit Pyramid Prints and Paperworks Studio, the invitational includes 30 artists from all over the country, although Washington and Baltimore artists have made a strong enough showing here to suggest they could have done it on their own. Amalie Rothschild, for example, learned paper-making at Pyramid, and proves her versatility in two striking, heavily embossed sculptural works; Joseph Roberson also proves to be a highly imaginative artist; he has created something that seems to cross a bird's nest with a television set.

The chief complaint here is that the IMF ought to take greater pains to professionalize its displays.

The show continues through Dec. 3, and hours are 9 to 5, Mondays through Fridays. Visitors must show personal identification to enter the building.