Int. J. Engng Ed. Vol. 22, No. 1, pp. 45±52, 2006 0949-149X/91 $3.00+0.00 Printed in Great Britain. # 2006 TEMPUS Publications.

The Evolution of Biological Engineering*

BERNARD Y. TAO, DOUGLAS K. ALLEN and MARTIN R. OKOS Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN, USA. E-mail: [email protected] The discipline of Biological Engineering is an academic structure evolving to address educational needs based on technologies arising from the new advances in the life sciences. This paper focuses on presenting concepts that distinguish Biological Engineering as a discipline, distinct from existing engineering disciplines, based on unique principles that define biology/living systems. It presents a perspective of Biological Engineering that focuses on the engineering of the inherent, central principles of living systems versus the application of externally engineered systems to existing living systems to alter their behavior or structure. Important concepts in educational curricular topics and concepts are also discussed, along with the historical background to the development of Agricultural Engineering into Biological Engineering. Keywords: biological engineering; agricultural engineering; historical overview; living systems

INTRODUCTION that distinguish it as a core science. In this article, we describe our definition of Biological Engineer- RECENT ADVANCES WITHIN the life sciences ing (BE) and the current and developing BE have changed the way we view biology and engin- curricula at Purdue University, and discuss the eering. The ability to quantitatively measure and evolution of Biological Engineering as a new model life processes is rapidly advancing histori- discipline. cally descriptive biology, to become a basis for engineering design and innovation. Interestingly, agricultural engineers recognized the need for this HISTORY OF ENGINEERING information almost a century ago but lacked the basic scientific foundations upon which to base The use of scientific principles to solve practical biological engineering principles. Today we antici- problems is a key characteristic of engineering. pate that, within a few decades, these unique Some notable early engineering marvels include fundamental principles of how living systems the architecture, pyramids, land monuments, and work will be much more extensively established irrigation and canalling practices that came into and Biological Engineering will emerge as a signif- existence around 2750 BC [1]. Egyptian epitaphs, icant new discipline for the future. Commensurate as well as existing landmarks, exemplify the work with biology becoming the basis for a new engin- of this time. The ancient Greeks had a different eering discipline is the need for a different kind of approach to engineering, concentrating as heavily engineering education. Purdue University's on aesthetics as on functionality, which agreed Department of Agricultural and Biological Engin- with the significance placed on virtue at this time eering is actively pursuing the development of this [2]. By 270 BC, the Greeks had created numerous educational model to meet the current and future mechanical, pneumatic, and hydraulic compo- demands of this fundamental new engineering nents, such as: musical instruments, clocks, discipline. springs, and water wheels to hoist water [2]. Historically, engineering disciplines have been Archimedes is known to have calculated buoyancy, developed to reflect the rational harnessing of a and centers of gravity for application in building core science, such as physics or chemistry, along ships at that time. At nearly the same time, the with mathematics, in response to meeting societal Chinese, responsible for the invention of gunpow- needs. Current engineering disciplines, such as der, were engineering underground tunnels, dams civil, mechanical, and electrical engineering, are and canals for the beneficial utility of water, and based primarily on physics, while chemical engin- `the Appian Way' of the Romans created roads eering incorporates chemistry. The more narrowly and channels still in use today. defined disciplines of petroleum, mining, ceramic, However, with all of these examples, the word aeronautical, food process, nuclear, agricultural, `engineer' still does not appear in any descriptive and aquatic engineering reflect tailored interests contexts until the Middle Ages [3]. Tertullian, an to very specific industries. While biology is early Christian author, applied the term `novum mechanistically dependent upon both chemistry extraneum ingenium', meaning ingenious device, in and physics, it incorporates many unique features describing battering rams in 200 AD, but the term `ingeniator', or engineer, was coined much later to describe the originators of military devices such as * Accepted 22 August 2005. crossbows, battering rams and trebuchets, during

45 46 B. Tao et al.

Fig. 1. ASAE timeline.

Gothic times [3]. The focus of engineering was Development of engineering as a discipline did concentrated on military achievements and agri- not occur until the Renaissance era. Primarily cultural development to improve food supplies. focused around civil and mechanical engineering, The Middle Ages also saw the conversion of numerous books recorded the technical details of many labor-intensive jobs to hydraulic, water- the design of structures, mills, siphons and the like, powered operations. Civil engineering emerged as indicating progress in the definition of these the first non-martial, professional engineering professions. (For a good review of some of the discipline, reflected by the cathedrals, bridges significant contributions to the Industrial Revolu- and canals and the Great Wall of China, all tion, see http://www.knockonthedoor.com/.) The constructed in this time period [2]. However, not development of railroad systems greatly expanded all of the achievements of this era were civil the role of these two types of engineers. Building engineering. Clock-making as a mechanical science railroads incorporated the unique skills that civil was also developed, and some of the first attempts engineers had previously employed in the design of in aeronautics occurred during this time-frame. canals and highways, as well as the science of The Evolution of Biological Engineering 47

Table 1. Standard agricultural engineering curriculum adopted itself. The Neolithic revolution that describes the from ISC* transformation of hunter-gatherers into farmers occurred some 10,000 years ago [4]. At this time Subject Description Percentage of Total Classwork humankind became more settled, forming villages, Agricultural engineering 14.2 domesticating animals and producing crops for General engineering 21.6 subsistence. The development of tools to aid in General agriculture 19.2 the daily chores related to food production are the Science 28.4 Cultural subjects 5.5 first examples of the agricultural engineering Elective 8.2 profession. At the beginning of the twentieth cent- Military and physical 2.7 ury, the profession of agricultural engineering was training formally established with the development of the * Taken from [5]Ðno indication as to where the other 0.2% is American Society of Agricultural Engineers in at. 1907. A comprehensive review of the history is given by R. Stewart in his book, Seven Decades mechanical propulsion disclosed by the mechanical that Changed America: A History of the American engineer. The emergence of mechanical engineer- Society of Agricultural Engineers [5]. Some of the ing was further elucidated during the Industrial highlights are shown on the timeline of Fig. 1 and a Revolution as steam power was harnessed for standard topical curriculum is given in Table 1. At multiple uses. the beginning of the society's professional devel- Chemical engineering as a profession was not opment, agriculture had progressed to encompass well established until near the end of the nineteenth the use of mules for horse power, along with century. Starting initially as industrial chemistry, steam-propelled threshers and a limited number chemical engineering saw tremendous growth of gasoline tractors. The demands for reduction in when fundamental thermodynamic principles of labor to make farming more efficient resulted in vapor-liquid equilibrium were established to put the application of the mechanical arts to farming. the industrial practice of petroleum distillation on Because most mechanical engineers had limited scientific foundations. Demands for petrochemi- interest in agriculture, agricultural engineering cals and fuels in the mid-1900s spurred the devel- developed to fulfill this need. To this extent, opment of chemical engineering fundamentals, most of the charter members of ASAE were such as unit operations, reaction kinetics, and trained in either mechanical or civil engineering, transport phenomena. As post-World War Two but with interests in agriculture. The challenge of American industries diversified into more complex uniquely defining agricultural engineering would processes to develop new polymers and plastics, be ongoing and, as with most disciplines, it chemical engineering enjoyed a golden era of continues even today. growth. The highly analytical and abstract critical The first notable example of this professional thinking structure of chemical engineering educa- society's evolution toward biology, highlighted by tion has allowed graduates to thrive in a variety Stewart [5], involved C.O. Reed and took place in of technical and economic disciplines beyond the 1930s. According to a disgruntled Reed, the traditional petroleum-based technologies. philosophy of ASAE suggested that, `agricultural engineering simply is the service of mechanical, civil, electrical, architectural, and industrial engin- HISTORY OF AGRICULTURAL eering taken to the industry of agriculture, as if we ENGINEERING were condescending to carry to agriculture some- thing from outside it.' Reed did not agree with this The origins of agriculturally based engineering notion and put forth his own vision, distinguishing curricula can be traced back to the roots of farming agricultural engineering as the `engineering of biology . . . This unique kind of engineering should be based on the energy transformations Table 2. Engineering societies founded* and transfer conducted by living cells; a methodol- ogy and efficiency concept so based would open a Society Founded new world to the agricultural engineer.' While ASAE headquarters embraced Reed's view, American Society of Civil Engineers 1852 American Institute of Mining Engineers 1871 suggesting this would confer distinction from American Society of Mechanical Engineers 1880 other engineering branches and therefore not American Institute of Electrical Engineers 1884 `step on the toes of others', apparently many Society of Naval Architects and Marine Engineers 1893 members did not agree with the idea and it had American Society of Heating and Ventilating 1894 died along with Reed by 1940. Engineers American Railroad Engineers' Association 1897 By the 1960s, chemical engineering, which was Society of Automobile Engineers 1904 founded at nearly the same time as agricultural Illuminating Engineering Society 1906 engineering (see Table 2), had become well-defined American Society of Agricultural Engineers 1907 in the area of unit operation, thanks in great part to American Institute of Chemical Engineers 1908 earlier work by McCabe, the clear quantitation of * Taken from [5]. vapor-liquid principles, and to transport processes 48 B. Tao et al. due to the ground-breaking work of Bird, Stewart uates will be proficient in the engineering and Lightfoot. Additionally the treatment of chemi- aspects associated with quantitative biology. cal reactor systems mathematically by Aris and 2. The core curriculum should significantly Amundson was resulting in widespread acceptance expand the capabilities of our graduates to of this profession [6]. The application of these effectively address the changing needs of society chemical engineering concepts to the agricultural for engineering related to biological systems. engineering discipline led to many improvements Within the last two decades, consumers have in the production of food and its subsequent increasingly placed more stringent requirements processing. While chemical engineering paved the on agriculturally derived product quality and way for quality of life improvements made by new convenience, as well as having greater sensitivity plastics, fuels, polymers and other synthetics from to environmental issues. As non-renewable petro- petroleum, agricultural engineering remained more chemical resources become less available, consu- focused on raw materials that were renewable and mer pressure for equivalent/superior products living. The renewable materials were generally from renewable resources will continue to grow. more heterogeneous, less stable, perishable, and These demands have created tremendous chal- created microbiological issues, leading to less lenges for the agricultural engineer. With the support compared to the synthetic alternatives. emergence of new biotechnologies, Agricultural However, they remained critical to fulfilling Engineering is uniquely positioned among the needs that synthetics could not, particularly food, engineering disciplines to play a pivotal role in feed, and fiber. The comparable advantage of the evolution of Biological Engineering. synthetics led to a resurgence in better defining the agricultural engineer. At the 1960 winter ASAE meeting in Memphis, G. W. Giles explained DEFINING BIOLOGICAL ENGINEERING his vision for the role of the agricultural engineer, alluding to `the internal mechanism of biological The common bases for all engineering disci- production and to the external operation and plines are science, mathematics and economics. environment that influence this mechanism.' He We will focus on the distinction conferred primar- stated, `Some may say that the science of biological ily by the first two core fields. The quantitative processes should be left to the pure scientist and modeling of natural phenomena, combined with that agricultural engineering should confine its Terrullian's novum extraneum ingenium to meet activities strictly to engineering practices. Regard- social or political needs, defines the significance less of whether it is called pure science or not, the of engineering. In this respect, biological engineer- fact remains that the mathematical relationships of ing is no different than any other engineering the physical to the biological processes are basic to discipline. Differentiation between the various developing superior engineering systems. Our fields comes from the set of scientific principles profession needs some fundamental (phenomeno- that are used and what sociological needs are logical) law(s) upon which to base our (technical) addressed. For example, some of the inherent judgments and guide our direction and pattern of differences between chemical engineering and growth for engineering the biological system. The mechanical engineering are found in differing core of our profession should be built on engin- emphases on statics/dynamics and mechanical eering laws governing the intricate complex properties of materials versus chemical reaction processes of plants and animals. This is the thing kinetics, rheology, unit operations, and vapor- that distinguishes agricultural engineering from liquid equilibria. Alternatively, industrial engineer- other engineering professions.' According to ing places a strong emphasis on modeling of Loewer [7], ASAE and higher academic institu- coordinated manufacturing operations and inter- tions supported this notionÐeven leading to actions with human operators to meet sociological/ changes in some of the agricultural engineering economic needs. curriculum namesÐbut the primary audience at Clearly defined concepts in biological systems the convention hearing Giles' speech, being (i.e. ability to reproduce, autonomous behavioral industrially based, was less inclined toward the nature, and self-maintenance, etc.) delineate the movement. life sciences from purely physically based branches More recently, in 1987, agricultural engineering of science. Although mechanistic principles from departments began to re-emphasize these ideals at other sciences, such as physics or chemistry, have a conference entitled `Project 2001ÐEngineering been applied to model biological systems, far fewer for the 21st Century,' resulting in development of specific quantitative principles have been uniquely several workshops to better shape the future direc- defined for living systems to date. For example, tion of the undergraduate curriculum. Of note Newton's Laws of Motion, Ohm's Law for elec- were the two primary conclusions about the core trical phenomena, or the Laws of Thermody- definition of the discipline: namics all represent fundamental laws in the fields of physics and chemistry. While biological 1. The core curriculum for our undergraduate systems, viewed as physical systems, must also engineering program should be based on the obey these constraints, the development of quant- biological sciences to the extent that our grad- itative laws distinguishing biological systems is The Evolution of Biological Engineering 49 comparatively in its infancy. Biology is predomi- micro level result in complex structures that have nantly still a descriptive, taxonomic science, based unique properties with their own definitive nature. on somewhat arbitrary classification criteria (e.g. Let us consider further the example of proteins. phenotype similarities, histology, DNA sequence It is generally accepted that protein structural homology, etc.). Some mechanistic principles are homology is more highly conserved than sequence well-recognized, such as the helical, double homology. The chemical compositions that allow stranded nature of DNA with 1:1 pairing of the proteins to fold explain the formation of these four nucleotides and Central Dogma (DNA ! structures, but why different sequences exist for RNA ! protein). However, basic quantitative the same structure and function involves evolu- laws upon which to distinguish and engineer tionary selection and possibly some probability. It living systems do not yet exist. In part, this is due is the combination of chemistry with other physical to the lack of a clear definition of what differenti- factors to create patterns in biology, many of ates a living system from inanimate physical which remain unexplained due to their complexity, systems. that distinguishes biological systems and therefore More than a century ago, Louis Pasteur, the relegates it and its engineering to unique study. father of modern microbiology, addressed this Through mathematically descriptive models of issue by asking two related questions: phenomena, consistent fundamental principles used in engineering design are created. Hence the 1. Can biological chemical structures be produced discipline of biological engineering awaits further from non-living precursors? elucidation of these laws before claiming true disci- 2. Can a living cell/system be created from only plinary uniqueness. It is likely that the hindered non-living components? discovery that these `biological laws' are at least The first question was effectively answered by partially a result of very small-size scales, the Fredrich Wohler in 1828 with the synthesis of complexity of living systems, and the qualitative urea. Since then, numerous equivalent examples nature of historical biology (i.e. over-dependence on ranging from basic Fisher-Killiani carbohydrate taxonomic descriptors) that has created animosity syntheses to complex protein and DNA chemical towards mathematics in researchers in the field. syntheses have been reported. The answer to the Recent scientific advancements in genetics, bio- second question, however, remains unanswered. informatics, and access to micro- and nanoscale Over the past several decades, several researchers measurement techniques have led to intense have initiated studies to address this question. In research and rapid development in our understand- the mid-1960s Arthur Kornberg, known originally ing of biosystems and will advance engineering for the discovery of DNA polymerase, worked to systems in biology. induce replication of an entire viral genome and Although this understanding is still limited, we was successful with the addition of a DNA ligase can examine conceptual inherent differences unveiled by Lehman and Gilbert independently in between living systems vs. non-living phenomena, 1967 [8]. The media's proclamation that he had remembering that the fundamental mechanistic created life in a test tube would seem a bit scientific foundations must be consistent (e.g. premature, as the system was not independently laws of thermodynamics, fluid dynamics, chemis- living, requiring a virus, and did not sustain its try, etc.). We propose four key differences that own existence. Nonetheless this work was a marve- distinguish the engineering of living systems from lous breakthrough at the time and the creation of non-living systems: biologically active molecules has since become rudimentary for those in the field. Still, whether 1. Living systems exist at cyclic, steady-state con- creation via virus or even using PCR techniques, ditions far from thermodynamic equilibrium, biologically active molecules alone are not for example metabolic cycles (e.g. TCA cycle). the definition of life. They alone are not self- 2. Living systems spontaneously export entropy to generating nor can they perform autonomous maintain internal structural organization, sta- self-maintenance. More recently, other researchers bility, and growth. This can be seen in the have started to explore membrane-based, self- ability to adapt to changing external conditions assembling systems which appear to have very to maintain internal stability (e.g. digestion/ limited autonomous replication properties [9±11]. excretion and perspiration). However, these authors recognize that, even 3. Living systems are inherently self-reproducing. with current capabilities to isolate/synthesize the The need and capability to reproduce is instinc- components of a living cell, simple combinations tive in all living systems, from single-cell struc- of these components does not create a living tures to the most complex mammals (e.g. system. mitosis, meiosis, and sporulation), though it is The distinction conferred upon the study of not necessarily advantageous to the parent. living systems advocated here is not a belief in 4. Living systems possess inherent, self-adaptable vitalismÐthe thought that physicochemical affinities for other living systems (or inorganic processes cannot explain living processesÐbut systems) at all levels, ranging from the mole- rather that the chemistry and physics of living cular to the whole organism. Examples of this systems, while familiar and explainable, at the idea include: antibodies, enzymes, protein 50 B. Tao et al.

synthesis/folding, intercellular microbial attrac- for their expertise with fermentations, and agri- tion, pets, children, mates. Orchestrating the cultural engineers with food/bioprocessing Bio- structural complexity of even the simplest medical engineering focuses on both physical and single-cell organism is still only possible energetic interfaces between physical engineered through the mediation of a living organism. systems and human living systems, exploring the biological responses to the implantation/applica- Modeling highly complex, compartmentalized tion of the physical systems. Novel advances in mixtures of synthetic or even biological macro- micro- and nanotechnologies with electrical/ molecules/components and quantifying their mechanical systems provide the opportunity to entropic content during steady state alone is a work at cellular and molecular size scales. formidable challenge. Adding the kinetics of self- This diversity of examples contains a common assembly, energetic initiation, and self-reproduc- theme: they are focused on developing externally tion is equally daunting. On top of this, our inability engineered systems/environments that interact to control/initiate/model highly non-equilibrium with a living system to alter its behavior/properties. thermodynamic systems makes the task of building A more fundamental definition of biological living systems de novo well beyond our current engineering would focus on altering existing inter- capabilities. Conceptually, this bears similarity to nal biological processes which control physical questions in physics related to the initial state of the attributes/behaviors. Big Bang theory or to current philosophical issues The distinction for biological engineering stems regarding evolution and creation theories. from what is being altered. Changing the environ- Similarly, developing quantitative descriptions ment (external) to the living matter is not bio- of these principles is highly challenging. Relatively logical engineering by our definition. Changing the simple molecular binding/attraction models have inherent, self-perpetuating identity of living matter been developed (e.g. the Michealis-Menten kinetic itself (internal) is the definition of biological en- reaction equation). However, given the complexity gineering. Our belief is that biological engineering of highly regulated, interconnected, multiphase, should fundamentally require more than just the multicomponent living systems, it is likely that application of external stimuli to living systems to novel forms of mathematical description may be affect how they act. Rather it should involve the needed. Put in a more prosaic form, how do you changing of the biological system itself, invoking a mathematically quantify love? controllable change that becomes a self-sustaining, While future advances in molecular biological integral part of the identity of the living system. techniques and methods will provide new tools to For example, a heart pacemaker does not affect researchers, the accomplishment of this goal will the identity of a person but provides a consistent require significant advances in the field of non- external stimulus that causes the heart tissue to act equilibrium thermodynamics and the understand- in a controlled fashion. We would define this as an ing of how living systems develop templates/ example of biomedical engineering, but not bio- patterns which are used to initiate new living logical engineering. Another example is the use systems. Developing these advances will likely of immobilized enzymes to produce DNA sensor require the formation of new concepts and laws chips. This application of biotechnology uses of how living systems work, which will be the basis electronic engineering principles associated with a of Biological Engineering. Hence, Pasteur's second component of a living system (antibodies, challenge may be the technological starting-point proteins), but it does not intrinsically change for Biological Engineering. biological systems. Hence this would not be an example of fundamental biological engineering by BIOLOGY AND ENGINEERING: our definition. On the other hand, the controlled THE NAME GAME genetic alteration of a metabolic pathway within an organism that causes it to overproduce a With recent advances in and social impacts of chemical intermediate is an example of biological the life sciences, many engineering disciplines are engineering, because this change becomes an inte- rushing to change their names to capture public gral part of the system, carried over in the repro- attention by incorporating some aspect of biology duction of the living cells to alter inherent in their names. Disciplinary names abound, behaviors. including bioengineering, biosystems engineering, biochemical engineering, biomolecular engineer- ing, biomedical engineering, bioresource engineer- THE EVOLVING ROLE OF AGRICULTURAL ing, and others. Each has a slightly different ENGINEERS AS BIOLOGICAL ENGINEERS applications focus, usually incorporating tradi- tional engineering disciplinary principles with Arguably, foundations of the historical Agricul- some aspect of a living system. Civil engineers, tural Engineering discipline have evolved to make for example, often work with waste treatment it closely oriented to the new discipline of Bio- bioremediation. Electrical/computer engineers are logical Engineering. The broad base of engineering developing hybrid electronic/living system inter- principles from many different disciplines faces and sensors. Chemical engineers are known combined with the focus on `engineering biology' The Evolution of Biological Engineering 51 as the basis for the discipline make it distinctive communications, professional responsibility, and from other physically based engineering disci- interpersonal skills. Within the last several plines. As G. W. Giles noted nearly half a century decades, society has placed increased demands on ago: `The core of our profession should be built on product quality, safety, and convenience. The engineering laws governing the intricate complex consumer is more sensitive to environmental and processes of plants and animals.' safety issues as well. As non-renewable resources Based upon the understanding that many differ- continue to diminish, societal demands for equiva- ent types of engineers will play a role in creating lent products from renewables will be greater than this discipline, what is the most logical role for ever. The abilities to produce and process large agriculturally based biological engineers? Certainly quantities of raw and processed feed stocks to one of the most promising areas is that of plant- replace petrochemicals will require a combination based biological engineering for bioproduction. of backgrounds in chemistry, biology, agriculture, Having worked with plants for production of and economics. These issues not only create food, from the beginning of the profession, tremendous challenges for the biological engineer through dependence of plant breeding, irrigation in the areas of food and pharmaceutical and and soils, growth, pest and herbicide management, industrial bioprocessing, but also highlight the through to harvest and post-harvesting, the back- increased visibility of biological engineers in every- ground of the agricultural engineer is clearly well day consumer societal needs. This visibility carries suited to developing plants as production systems both important benefits and responsibilities that for novel compounds through biological engineer- fall on the shoulders of biological engineers. In ing. This incorporates a host of application addition to a high level of technical skills, bio- demands, such as the renewable production of logical engineers must also be able to effectively fuels, chemicals, foods, and nutriceuticals, and communicate the potential impacts and risks of thus these topics of study would seem to be the their discipline in public and political arenas. most logical areas whereby traditional agricultural Examples are the development of genetically engineers could benefit society. altered plants or animals for food or industrial products or the development of sophisticated micro/nanoscale living biosensors. The potential CURRICULAR ISSUES IN BIOLOGICAL impacts of these on intimate everyday human ENGINEERING EDUCATION activities in food and medicine are staggering, both economically and socially. The ability of the The ability to quantitatively measure and model biological engineer to evaluate, recognize, and life processes is rapidly moving qualitative biology inform society of the risks and benefits of these toward becoming a basis for engineering design technologies is an important part of the educa- and innovation [12, 13]. This growth has high- tional process. lighted the need for highly interdisciplinary educa- An example of a currently evolving Biological tional methods, from both the science and Engineering curriculum to address these issues engineering perspectives. Building an integrated is Purdue's Biological and Food Processing educational curriculum in BE will require categor- Program, which can be found at https://engineering. izing basic engineering and biological science purdue.edu/ABE/Undergrad/fpe.whtml. concepts, facts, and examples in a way that demon- strates their inherent relationships. This task must CONCLUSIONS entail more than a curriculum redesign that simply shuffles existing courses in different departments. Today the historical convergence of advances in It will require a high level of collaboration between biology and societal needs for renewable sources of current faculties from a variety of disciplines, energy and industrial materials, human/animal embracing the idea of comprehensive, interdisci- welfare, and new materials have created an exciting plinary education. The willingness to operate in a environment for the creation of a new engineering `give and take' environment to identify key discipline based on biology. While current engin- concepts and examples without dogmatic insis- eering disciplines will expand to incorporate tence along traditional disciplinary educational features of the life sciences, the opportunity exists lines will be critical. For example, finding ways for a new discipline, Biological Engineering. The to merge key concepts in biology, physics, and identity of Biological Engineering should be based chemistry into thermodynamics or reaction on establishing fundamental engineering/scientific kinetics courses that meet engineering modeling principles based on concepts that uniquely distin- imperatives is needed. This will require the rede- guish living systems, as well as understanding their sign of current disciplinary courses to become relationship to the existing physical sciences and courses in engineering biophysics or biochemistry. engineering principles. While historical evolution This process will require substantial collaborative from Agricultural Engineering to Biological En- efforts among faculty and departmental adminis- gineering exists, development of new curricular trations, which will be an evolutionary process. models and integrated topical structures are In addition to technical skills, Biological needed to educate biological engineering students Engineering must emphasize critical thinking, and create a clear, distinct identity for graduates. 52 B. Tao et al.

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Bernard Tao is a Professor in Agricultural and Biological Engineering and holds the ISB Chair for Soybean Utilization at Purdue University. He received B.Sc. and M.Sc. degrees in Chemical Engineering from the Massachusetts Institute of Technology and a Ph.D. degree in chemical engineering from Iowa State University. He teaches courses in thermo- dynamics, reaction kinetics, mathematical modeling, and engineering ethics and conducts research in recombinant genetic engineering of enzymes and structural proteins and development of new industrial products from biomaterials.

Douglas Allen is currently a post-doctoral student at Michigan State in plant biology genetics. He received his B.Sc. in Agricultural Engineering from Iowa State University, and M.S. and Ph.D. degrees from Purdue University in Agricultural and Biological Engineering.

Martin Okos is a Professor in Agricultural and Biological Engineering at Purdue University. He earned his B.Sc. in Food Science and M.Sc. and Ph.D. in Chemical Engineering from The Ohio State University. He teaches courses in food process engin- eering and conducts research in computer-aided design of food processes, heat and mass transfer in foods, fermentation and biological reactor design, and properties of food and biological products.