Focus on Research
Penn State Intercom......November 7, 2002

'York' honors
slave's epic journey

By Vicki Fong
Public Information

For Bruce Trinkley, the spark for his new musical drama "York: The Voice of Freedom" was kindled during the creation of another project, a dramatic cantata, "The Last Voyage of Captain Meriwether Lewis."

As the Penn State composer and his librettist partner, Jason Charnesky, delved deeper into Lewis' story of the transcontinental expedition to the West, fame and glory, and eventual decline into suicide, other figures on the Lewis and Clark expedition grew equally intriguing.

"As we tried to tell the epic story of the expedition in 30 minutes of song, I was overwhelmed with the richness, depth and sheer number of peoples and stories the voyage entails," recalled Trinkley, a professor of music. "So many stories needed to be heard -- Sacajawea's intrepid journey with her child, the two captains' unwavering determination, the harrowing passage across the Bitterroots, the sublime elation on first sighting the Western Sea. But one story among all of these captured me and demanded that I try to tell it in its fullness. One strange and funny incident leapt out of the journals for me: that single incident of York, the slave, amusing the Indians with talk of his young life spent as a bear who snacked upon the occasional Indian child.

"Who was this man? What moved him? How did his great adventure change him? And where did his striving and dreams take him?" he asked.

As Trinkley and Charnesky, a University graduate student in English, conducted research into York's life, they found that he had been a slave, born into the household of William Clark's family and probably began his service to Clark (who was roughly the same age) as a boy.

When Clark joined with Lewis to search for a route from the Missouri River to the Pacific Ocean, he took his slave with him. York worked alongside the other men. He carried a gun and shared in the dangers and the toil and traveled to the shore of the Pacific Ocean. York was the only African- American member of the Lewis and Clark expedition, and for all intents and purposes he served as an equal member and was granted freedoms and responsibilities beyond anything he had known back East.

When the expedition encountered American Indians who had never seen a black man before, York was a marvel to them. His black complexion was seen as a mark of great honor. The thing which marked York as property in the United States was seen as a sign of worth and dignity by the Indians.

When the expedition returned to the United States, every member received not just the money and land they were promised by the government, but double portions of land and money. Only York received no payment because as a slave, he was owed nothing.

"Our knowledge of York's life is really very sketchy," Charnesky said. "We know that York was married and that his wife was a slave owned by a different master. We know that his wife's master moved away and that William Clark forbade York from visiting her. We know that York agitated for his freedom and that William Clark denied his requests. We know that Clark grew increasingly annoyed at his slave's willfulness. We know that in desperation or disgust Clark hired York out for a time to a severe master. And we know that through all of this York continued to demand his freedom. It is this defiant spirit of freedom that our music drama honors."

The lead roles will be performed by New York City Opera performers Leonard Rowe, baritone, as York; and Tamara Haskin, soprano, as his wife Mary. Brett Hyberger, guest artist, sings the role of William Clark, and Norman Spivey, associate professor of music, performs the role of Meriwether Lewis. The musical drama will have its world premiere on Nov. 14 and run through Nov. 16 at the University Park campus, in conjunction with a University conference "Lewis & Clark: The Unheard Voices" that will address the impact of the 1803-1806 expedition on the lives of American Indians, African- Americans and other minorities.

"The coming bicentenary of the Lewis and Clark expedition will, no doubt, be the occasion for the creation of many other performance pieces," Trinkley noted. "But 'York: The Voice of Freedom' is unique, I believe, among these in giving voice to the part that African-Americans and Native Americans played in our national drama. 'York' will challenge audiences to grapple with the realities of America's past and present in order to fulfill the promise of our future. We still face the contemporary discussion of what is, after all, the most important question faced by every American citizen: What has our past truly been, and how must we live in the present to honor that past?"

Circuit transfers more power
from shakes and rattles

University engineers have optimized an energy harvesting circuit so that it transfers four times more electrical power out of vibration -- the ordinary shakes and rattles generated by human motion or machine operation.

Using their laboratory prototype, which was developed from off-the-shelf parts, the researchers can generate 50 milliwatts. Although they haven't tried it, they believe the motion of a runner could be harnessed to generate enough power to run a portable electronic music device. By comparison, simple, un-optimized energy harvesting circuits, for example the type used to power LEDs on "smart" skis, can only generate a few milliwatts. The researchers said the new circuit offers an environmentally friendly alternative to disposable batteries for wearable electronic devices or for wireless communication systems. In addition, the circuit could be used in sensor and monitoring networks that manage environmental control in office buildings, robot control and guidance systems for automatic manufacturing, warehouse inventory; integrated patient monitoring, diagnostics, drug administration in hospitals, interactive toys, smart home security systems and interactive museums.

Research on the new circuit was completed by Geffrey K. Ottman, former University master's degree student; Heath Hofmann, assistant professor of electrical engineering; Archin C. Bhatt, former University master's degree student; and George A. Lesieutre, professor of aerospace engineering and associate director of the Center for Acoustics and Vibration.

Lesieutre explained that, like other energy harvesting circuits, the new device depends on the fact that when vibrated so that they bend or flex, piezo-electric materials produce an alternating or AC current and voltage. This electrical power has to be converted to direct current or DC by a rectifier before it can be stored in a battery or used. Hofmann added that the magnitude of the piezoelectric material's vibration determines the magnitude of the voltage.

Using an analytical model, the team derived the theoretical optimal power flow from a rectified piezoelectric device and proposed a circuit that could achieve this power flow. The circuit includes an AC-DC rectifier and a switch-mode DC-DC converter to control the energy flow into the battery. The researcher noted that using an approach similar to one used to maximize power from solar cells, the team developed a tracking feature that enables the DC-DC converter to continuously implement the optimal power transfer and optimize the power stored by the battery.

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